Who uses PS/2 instead of USB?

[Keytrun]

Any of you Geek kittens use PS/2 (little purple adapter) instead of USB? I personally can't find the need for any more than 6 NKRO, so I don't understand why anyone WOULD use PS/2 - though I'm interested to see how many people do use it.

In all the research I've done I can't really find anything definitive that says that USB performs better than PS/2 in any way. I read that most new motherboards don't really invest a lot into their PS/2 connections, which makes me wonder if that alone could make USB perform better - maybe latency wise? I don't care about any more than 6 key rollover. I just want to have the best, lag free performance I can get.

[tuxsavvy]

I personally don't know much about PS/2 being that much more superior to USB in terms of performance-wise. However as a more logical point of view:

• A keyboard plugged into dedicated PS/2 plug frees up one USB spot. This is probably beneficial if one does not have too many USB ports to begin with and having to rely on USB hubs as such to expand one's peripheral connectivity on the machine.
• A keyboard plugged into dedicated PS/2 socket (on the actual machine if it features one) usually gets detected first before the machine allows USB inputs. On older machines for instance the BIOS may not recognise a USB keyboard is plugged in via USB when it detects no keyboard has been plugged through the PS/2 port.
• A keyboard plugged into PS/2 plug does not make one think too much about the lag that may occur if lets say a USB hub is used and there are many peripherals communicating with each other via the same bus and the same port on the machine. This maybe seen as a bit of a performance issue because PS/2 on computers are dedicated to keyboards (also mouse but mainly keyboards).
• Unlike USB where there are multiple various devices capable of communicating on the same sort of technology, an unpowered USB hub may for instance give all the power from the machine to a power hungry peripheral. This would in short leave other devices power starved.

[atlas3686]

I use PS/2 pretty much the same logic as tuxsavvy. Also my annoying Asus maximus extreme board has an issue where occasionally USB ports all die and I need to reinstall USB drivers which is difficult to do without a keyboard and mouse (since they would both run on USB) so this helps with that too

[rowdy]

I'm not sure I've got any computer still in service with a PS/2 port.  Many of the old computers have PS/2, but I no longer use them.

On the older computers I would probably use PS/2.

On the newer ones - USB only (and I have PS/2 to USB adaptors).

[Grendel]

I do if I can, why waste a perfectly good port ? PS/2 is about as fast as a USB 2.0 full speed connection polled at 1ms but without putting any load on the CPU, I don't have to think about KRO,  and it frees up a USB port.

[Hellmark]

For my main keyboard, I am currently using PS/2. One reason is that it keeps a free USB port, and I simply don't have an adapter yet. I do plan on making a RUMP at some point, just haven't had the time.

[aicrono]

I've used a P/S2 port for my keyboard whenever it was possible as long as I can remember. In fact, I specifically look for keyboards that still have one when I build a new computer. It's nice saving USB ports for other devices and it has always worked in the past for me when a USB keyboard hasn't (BIOS being the best example). NKRO is nice but most/if not all decent mechanical keyboards have enough of a roll over to work for just about every situation. The only downside is that P/S2 ports aren't typically hot swappable and you have to have whatever device is plugged into it before you power it on. No big deal but can be a hassle when troubleshooting sometimes.

[0100010]

Use PS2 because of BIOS issues historically, which I still encounter to this day at work.

[Keytrun]

Is there something that prevents PS/2 from allowing me to press and hold multiple keys and have them continuously repeat? Like on USB I could hold J and K and it would type out jkjkjkjkjkjk for as long as I held it, provided that I pressed them both at the exact same time. I haven't been able to get two keys to repeat once since I've switched to PS/2.  Now I get jkkkkkkkkkkkkkkk. Any idea what that's about?

[JoeUser]

I'm using PS/2 for my AT keyboard!

[Linkbane]

Is there something that prevents PS/2 from allowing me to press and hold multiple keys and have them continuously repeat? Like on USB I could hold J and K and it would type out jkjkjkjkjkjk for as long as I held it, provided that I pressed them both at the exact same time. I haven't been able to get two keys to repeat once since I've switched to PS/2.  Now I get jkkkkkkkkkkkkkkk. Any idea what that's about?

It doesn't do that on my USB keyboard, either.

[JoeUser]

Is there something that prevents PS/2 from allowing me to press and hold multiple keys and have them continuously repeat? Like on USB I could hold J and K and it would type out jkjkjkjkjkjk for as long as I held it, provided that I pressed them both at the exact same time. I haven't been able to get two keys to repeat once since I've switched to PS/2.  Now I get jkkkkkkkkkkkkkkk. Any idea what that's about?

I've never heard or seen this ever happen.

kjjjjjjjjjjkkkkkkkkkkjkkkkkkkkkk <--- Nope. Laser/SMK/PS/2

jkkkkkjjjjjjjjjjjjjjjjjjjjjjkjjjjjjjkkkk <--- Nope. KBT Pure/MX Blues/USB

[terran5992]

Meeee

My korean custom need to be plugged to a ps2 port

[eddie]

I don't, but if i had the option I would probably use ps/2

[terran5992]

I don't, but if i had the option I would probably use ps/2

You should. NKRO FTW

[Tony]

Whenever possible. I have two Compaq MX 11800s, they still works.

[MKULTRA]

My PC has PS2 on it so I use it whenever I can.  Useful for freeing up a USB port.

[Candyflip]

I don't use it for the NKRO since I don't think its necessary to click more than 4-5 at a time the most. I use it cos I am on an old piece of s*** rubber dome keyboard at the moment, can't wait to decimate it.

[JPG]

At home I have a PS/2 port so I use it.


At work my laptop doesn't have one so I am stuck with usb. It's still working well, but I would like to have the option of the ps/2 port.

[osi]

As others have stated, using ps/2 frees up a USB port.

Also, I like the fact of ps/2 interrupts vs usb polling. Probably woudln't notice a difference in real world though honestly.

[Photekq]

I use whatever's easiest. If the keyboard has a USB plug I'll use USB. If the keyboard has a PS2/DIN plug I'll use PS2. The less adapters the better.

[randomist]

I use PS/2 whenever I can. Most reasonably high end or gaming motherboards have PS/2 connections and I specifically look for ones that do when buying. The only reason I can think of for using USB preferentially is for additional features like LED backlighting.

[nickr]

The only reason I can think of for using USB preferentially is for additional features like LED backlighting.

You have to reboot when swapping out PS/2 connections.  If you're planning on testing keyboards or switching keyboards for different uses throughout the day or week then you'll probably want USB.  If you never change your keyboard then who cares what connection you use, unless you're dead set on NKRO (which is another debate).

[tuxsavvy]

The only reason I can think of for using USB preferentially is for additional features like LED backlighting.

You have to reboot when swapping out PS/2 connections.  If you're planning on testing keyboards or switching keyboards for different uses throughout the day or week then you'll probably want USB.  If you never change your keyboard then who cares what connection you use, unless you're dead set on NKRO (which is another debate).

I personally have to say rebooting computer when swapping out PS/2 connection is moreso limited to OS/platform specifics. I believe windows has that issue where it supposedly it "initialises" the keyboard only at startup. The said issue does not happen as I am running linux here. I have swapped between a few PS/2 keyboards and have had more than one keyboard plugged in at a time, even typed on two different keyboards without any issues of having to reboot my machine.

That said, there are probably ways for one to be able to circumvent the need to reboot on windows for instance with PS/2 keyboard. I guess the use of something like KVM (keyboard, video, mouse) may forgo such requirements as the controller on the KVM usually tells the machine that the keyboard is always plugged in even though on the KVM itself there are no keyboards attached. That said, KVM with PS/2 are somewhat becoming a little more rare.

[terran5992]

I don't use it for the NKRO since I don't think its necessary to click more than 4-5 at a time the most. I use it cos I am on an old piece of s*** rubber dome keyboard at the moment, can't wait to decimate it.

Well if your keyboard is capable . Why not?

[nickr]

The only reason I can think of for using USB preferentially is for additional features like LED backlighting.

You have to reboot when swapping out PS/2 connections.  If you're planning on testing keyboards or switching keyboards for different uses throughout the day or week then you'll probably want USB.  If you never change your keyboard then who cares what connection you use, unless you're dead set on NKRO (which is another debate).

I personally have to say rebooting computer when swapping out PS/2 connection is moreso limited to OS/platform specifics. I believe windows has that issue where it supposedly it "initialises" the keyboard only at startup. The said issue does not happen as I am running linux here. I have swapped between a few PS/2 keyboards and have had more than one keyboard plugged in at a time, even typed on two different keyboards without any issues of having to reboot my machine.

That said, there are probably ways for one to be able to circumvent the need to reboot on windows for instance with PS/2 keyboard. I guess the use of something like KVM (keyboard, video, mouse) may forgo such requirements as the controller on the KVM usually tells the machine that the keyboard is always plugged in even though on the KVM itself there are no keyboards attached. That said, KVM with PS/2 are somewhat becoming a little more rare.

Those are good points.  I just assumed the OP is a gamer given the usage of "lag free performance" and if you're a gamer then you're almost certainly using Windows as your host OS.

[tuxsavvy]

The only reason I can think of for using USB preferentially is for additional features like LED backlighting.

You have to reboot when swapping out PS/2 connections.  If you're planning on testing keyboards or switching keyboards for different uses throughout the day or week then you'll probably want USB.  If you never change your keyboard then who cares what connection you use, unless you're dead set on NKRO (which is another debate).

I personally have to say rebooting computer when swapping out PS/2 connection is moreso limited to OS/platform specifics. I believe windows has that issue where it supposedly it "initialises" the keyboard only at startup. The said issue does not happen as I am running linux here. I have swapped between a few PS/2 keyboards and have had more than one keyboard plugged in at a time, even typed on two different keyboards without any issues of having to reboot my machine.

That said, there are probably ways for one to be able to circumvent the need to reboot on windows for instance with PS/2 keyboard. I guess the use of something like KVM (keyboard, video, mouse) may forgo such requirements as the controller on the KVM usually tells the machine that the keyboard is always plugged in even though on the KVM itself there are no keyboards attached. That said, KVM with PS/2 are somewhat becoming a little more rare.

Those are good points.  I just assumed the OP is a gamer given the usage of "lag free performance" and if you're a gamer then you're almost certainly using Windows as your host OS.

Arguably that is true, gamers are mainly running on windows platform. I guess the day when virtualisation becomes as fast as running OS natively ont he same said machine it might even spell the end for one to worry about a "full machine reboot". In saying so, such case is already slowly becoming a viable reality.

[Phagocytosis]

I would if I had a PS/2 port :[

[Reomero]

The only time I needed NKRO over PS/2 was when I was playing Curve Fever with some friends using the same keyboard.

[tuxsavvy]

I would if I had a PS/2 port :[

I guess there will be people who will still try to immortalise certain connectors, much like how serial and parallel connectors were once abundant and now are becoming fairly rare (almost to the point of extinction). Actually there is one example here for a PS/2 connector via PCI card (source):

 )
Although there are caveats with the said product as one newegg customer pointed out:

Pros:  It works - in Windows.



   Cons:  First, I bought this as a solution to not having a PS/2 port for my mechanical keyboard so I could get SOME functionality of my NKRO. This does not however provide full NKRO as it is still limited as a USB port would be to 6key NKRO.

Secondly.... IT DOESN'T WORK DURING BOOT UP/POST. This is very irritating, and I kind of guessed it would be the case before I bought it. It works fine in Windows, but before loading windows... nothing.



   Other Thoughts:  If you REALLY need a PS/2 port, get one. If you are thinking "man, PS/2 will make my keyboard cool-er!" or "I can install windows with my old ps/2 keyboard with this!"..... this isn't the product for you, you're deluding yourself.

[Leslieann]

I use PS/2 pretty much the same logic as tuxsavvy. Also my annoying Asus maximus extreme board has an issue where occasionally USB ports all die and I need to reinstall USB drivers which is difficult to do without a keyboard and mouse (since they would both run on USB) so this helps with that too

Install something like TeamViewer or VNC, that way you can re-install from a cell phone or something.
Uninstall usb, update the bios and re-install, it might fix it. Also if you have USB 3 and 2, put peripherals on USB2 if they are not USB 3, they may be less likely to have problems.

You have to reboot when swapping out PS/2 connections.  If you're planning on testing keyboards or switching keyboards for different uses throughout the day or week then you'll probably want USB.  If you never change your keyboard then who cares what connection you use, unless you're dead set on NKRO (which is another debate).

I personally have to say rebooting computer when swapping out PS/2 connection is moreso limited to OS/platform specifics. I believe windows has that issue where it supposedly it "initialises" the keyboard only at startup. The said issue does not happen as I am running linux here. I have swapped between a few PS/2 keyboards and have had more than one keyboard plugged in at a time, even typed on two different keyboards without any issues of having to reboot my machine.

That said, there are probably ways for one to be able to circumvent the need to reboot on windows for instance with PS/2 keyboard. I guess the use of something like KVM (keyboard, video, mouse) may forgo such requirements as the controller on the KVM usually tells the machine that the keyboard is always plugged in even though on the KVM itself there are no keyboards attached. That said, KVM with PS/2 are somewhat becoming a little more rare.

I used to think it was OS specific, but I have found it's a combination of board, drivers and OS. I have had an XP and Win7 system both come unplugged and plugging them back in still worked, but most of the time it means a reboot. Changing to a different model however almost always means a reboot. Linux is certainly less fickle about it. Strangely, I've found that the HID Liberator doesn't always work as PS2 on some board and OS combinations during the initial OS install, yet works fine as USB. It also won't let me go into safe mode in Windows, all of which may be fixed with an update, I just haven't looked into it.



For me, ps2 has no performance advantage really (6kro is fine), but more importantly, my computer is 8 feet below me in the basement, and if it gets tugged or something and comes undone, it means a trip downstairs (and my knees hate stairs).  As for ports, I have to run long cables anyhow, so using USB cuts down on the cables running through the floor.

[tuxsavvy]

You have to reboot when swapping out PS/2 connections.  If you're planning on testing keyboards or switching keyboards for different uses throughout the day or week then you'll probably want USB.  If you never change your keyboard then who cares what connection you use, unless you're dead set on NKRO (which is another debate).

I personally have to say rebooting computer when swapping out PS/2 connection is moreso limited to OS/platform specifics. I believe windows has that issue where it supposedly it "initialises" the keyboard only at startup. The said issue does not happen as I am running linux here. I have swapped between a few PS/2 keyboards and have had more than one keyboard plugged in at a time, even typed on two different keyboards without any issues of having to reboot my machine.

That said, there are probably ways for one to be able to circumvent the need to reboot on windows for instance with PS/2 keyboard. I guess the use of something like KVM (keyboard, video, mouse) may forgo such requirements as the controller on the KVM usually tells the machine that the keyboard is always plugged in even though on the KVM itself there are no keyboards attached. That said, KVM with PS/2 are somewhat becoming a little more rare.

I used to think it was OS specific, but I have found it's a combination of board, drivers and OS. I have had an XP and Win7 system both come unplugged and plugging them back in still worked, but most of the time it means a reboot. Changing to a different model however almost always means a reboot. Linux is certainly less fickle about it. Strangely, I've found that the HID Liberator doesn't always work as PS2 on some board and OS combinations during the initial OS install, yet works fine as USB. It also won't let me go into safe mode in Windows, all of which may be fixed with an update, I just haven't looked into it.



For me, ps2 has no performance advantage really (6kro is fine), but more importantly, my computer is 8 feet below me in the basement, and if it gets tugged or something and comes undone, it means a trip downstairs (and my knees hate stairs).  As for ports, I have to run long cables anyhow, so using USB cuts down on the cables running through the floor.

It has been awhile since I last used windows that heavily. Though I guess from the way you phrased it, it sounds like it could then be a controller (on the motherboard?) issue. Not sure though.

I have had some issues as well thinking of it where certain motherboards would refuse to detect PS/2 keyboards even if they were plugged into the motherboard (via the back). It would refuse to go into BIOS setup and would do anything else. Those were Asus motherboards from memory. At the time I cannot recall if I had tried USB keyboards or making my PS/2 keyboard go through an adapter.

About performance specifics, I too am not really fussy about KRO at all. I guess mainly these days I really don't game much on my computer and even if I were to game, I would just plug in some old RD keyboard with PS/2 if need be. That said, I can imagine it would be annoying if there were either bandwidth issue (when using USB hubs along with other USB devices that heavily utilises the USB bandwidth) and/or power starved USB device (when using unpowered USB hubs for instance).

Holy cow, 8 feet into the basement?  At that point if I were to constantly accidentally tug and (as a result) yank my the cable out of the back (or front) of the computer from that far) I would have considered options such as "puttying up" the floor for instance in a bid to restrict the amount of movement for the cables. The idea can be a bit of overkill but there maybe are possible other alternatives. Maybe even using something like cable wrapper or zip (cable) tie to prevent too much movement with the cables especially when bundled together. Initially such work will be hard but I guess it may pay for itself in the end.

[laffindude]

PS2, because I want higher repeat rate for my mouse keys.

[Betty]

I remap a lot of keys on my keyboards to come as close as I can to the HHKB layout, except of course on the HHKB itself.
So I need lsusb to detect the keyboard and to let the cron job do the work. Otherwise with PS/2 I would have to do that by myself
everytime I change the keyboard.
But this is the only reason and I never recognized any improvement over PS/2 except NKRO.

[TacticalCoder]

Any of you Geek kittens use PS/2 (little purple adapter)

I used to because I was on Model Ms and didn't bother with an adapter... Until I read on GH years ago that you could damage/brick your motherboard by plugging/unplugging PS/2 while the computer was on. Yet I was sure PS/2 was hotswap: for years I've plugged/unplugged PS/2 on countless machines (including servers) and never had any issues.

I don't know if these "plug PS/2 and screw your mobo" are real or if I was just lucky but in doubt I ordered a few "blue cubes" PS/2-to-USB adapters for my Ms and never used PS/2 again since then...

Now the point is moot as I switched to HHKB, which comes with USB anyway 

[tuxsavvy]

I remap a lot of keys on my keyboards to come as close as I can to the HHKB layout, except of course on the HHKB itself.
So I need lsusb to detect the keyboard and to let the cron job do the work. Otherwise with PS/2 I would have to do that by myself
everytime I change the keyboard.
But this is the only reason and I never recognized any improvement over PS/2 except NKRO.

I was looking at ways to find how to get all the keys and shortcuts working with KDE4 and my HHKB Pro JP. As I started broadening my search (first by looking at Japanese websites for a few reasons) I came stumbling across a really nifty program which will not only detect USB keyboard but also the PS/2 keyboard. The command is:

Code: [Select]

xinput --listRight now with my HHKB Pro JP plugged in via USB port (and placed physically in the background with keyboard roof on) and using APC Clicker F-21 via DIN -> PS/2 adapter which is then plugged into the back of my machine with a proper PS/2 port the result of my xinput --list shows this:

Code: [Select]

⎡ Virtual core pointer                          id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ Logitech USB-PS/2 Optical Mouse           id=8    [slave  pointer  (2)]
⎣ Virtual core keyboard                         id=3    [master keyboard (2)]
    ↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
    ↳ Power Button                              id=6    [slave  keyboard (3)]
    ↳ Power Button                              id=7    [slave  keyboard (3)]
    ↳ AT Translated Set 2 keyboard              id=9    [slave  keyboard (3)]
    ↳ PFU Limited  HHKB Professional JP         id=10   [slave  keyboard (3)]
I thought I might as well give you the heads up with this nifty program in favour of lsusb when it comes to dealing with PS/2 keyboards. You can see my APC Clicker F-21 keyboard is being noted as "AT Translated Set 2 keyboard". I do not know if all PS/2 keyboards will appear like this, or would only the DIN -> PS/2 keyboards would appear like this or whatever but at least with xinput I could not only see my keyboards and mouse plugged in but for the USB based devices I could easily see their vendor and product names being mentioned. DIN and PS/2 keyboards for instance lacks "ID sending" scheme so it may most likely appear as some generic keyboard as you can see here.

Apparently the article also went on that one can also disable/enable inputs as well which was quite interesting. Though unrelated.

I did not get my keyboard shortcuts to work but that again is another story. xmodmap clearly is doing its job but KDE4 isn't.

Source (Japanese only):

• http://qiita.com/ka_/items/47f12dd17780e33155a7

[Leslieann]

About performance specifics, I too am not really fussy about KRO at all. I guess mainly these days I really don't game much on my computer and even if I were to game, I would just plug in some old RD keyboard with PS/2 if need be. That said, I can imagine it would be annoying if there were either bandwidth issue (when using USB hubs along with other USB devices that heavily utilises the USB bandwidth) and/or power starved USB device (when using unpowered USB hubs for instance).

Holy cow, 8 feet into the basement?  At that point if I were to constantly accidentally tug and (as a result) yank my the cable out of the back (or front) of the computer from that far) I would have considered options such as "puttying up" the floor for instance in a bid to restrict the amount of movement for the cables. The idea can be a bit of overkill but there maybe are possible other alternatives. Maybe even using something like cable wrapper or zip (cable) tie to prevent too much movement with the cables especially when bundled together. Initially such work will be hard but I guess it may pay for itself in the end.

There is no reason for PS2 except lack of ports, or using an old keyboard. Almost every excuse can be debunked. NKRO is particularly easy to debunk as being better.
Polling rates and bandwidth are especially easy to debunk as USB can poll at 4800per second, and a keyboard will never even come close to using what even USB 1 can handle in terms of bandwidth.


I use thick, heavy shielded and sleeved DVI cables which are supported, and all others are strapped to those with velcro.
I only had one cord come loose but it was loose as I was doing a test and forgot to go back and strap it in. The only real problem I had was with my monitors. I started out with mini display port to DVI adapters which worked great, but they burned out after about a year or two. The 15 foot hdmi cables, which claim 50 foot limits, couldn't handle the 15 feet reliably. They allowed the signal to degrade enough that my monitors fell out of sync. They may handle 50 feet for tv, but not a monitor. Thinking it was a video card issue, I contacted XFX, who was fantastic, but before we did anything, I connected some old, shorter cables to test with and found everything was fine. I now use the previously mentioned DVI cables.


I have a custom built box on my desk, which contains a powered USB 3 hub for the desktop and two esata ports (desktop and file server). It also contains power and hdd lights and power switches for 4 systems in my basement as well as a power switch to turn on and off my modem and router remotely. Makes things much easier. I plug in a usb dvd rom when necessary, which is about once a year. I also have a powered USB 2.0 hub under the desk connected to the desktop (as opposed to the USB 3.0 hub), which is where my keyboard and mouse connect, this ensures a clean signal for them regardless of what I connect to the USB 3.0 hub.

The nice thing about this setup is that the computer sits in a cool room (basement), where I can't see or hear it. It also keeps from having to run the air conditioner as much upstairs. It's actually saved me money in the long run, I use less electricity and there is no need to invest in quieter fans or power supplies.

Any of you Geek kittens use PS/2 (little purple adapter)

The "blue cube" ps2 to usb adapter?
I did up until the adapter or my Model M quit, I haven't had time or been bothered to see what failed. It worked well for several years up to that point.

[tuxsavvy]

About performance specifics, I too am not really fussy about KRO at all. I guess mainly these days I really don't game much on my computer and even if I were to game, I would just plug in some old RD keyboard with PS/2 if need be. That said, I can imagine it would be annoying if there were either bandwidth issue (when using USB hubs along with other USB devices that heavily utilises the USB bandwidth) and/or power starved USB device (when using unpowered USB hubs for instance).

Holy cow, 8 feet into the basement?  At that point if I were to constantly accidentally tug and (as a result) yank my the cable out of the back (or front) of the computer from that far) I would have considered options such as "puttying up" the floor for instance in a bid to restrict the amount of movement for the cables. The idea can be a bit of overkill but there maybe are possible other alternatives. Maybe even using something like cable wrapper or zip (cable) tie to prevent too much movement with the cables especially when bundled together. Initially such work will be hard but I guess it may pay for itself in the end.

There is no reason for PS2 except lack of ports, or using an old keyboard. Almost every excuse can be debunked. NKRO is particularly easy to debunk as being better.
Polling rates and bandwidth are especially easy to debunk as USB can poll at 4800per second, and a keyboard will never even come close to using what even USB 1 can handle in terms of bandwidth.


I use thick, heavy shielded and sleeved DVI cables which are supported, and all others are strapped to those with velcro.
I only had one cord come loose but it was loose as I was doing a test and forgot to go back and strap it in. The only real problem I had was with my monitors. I started out with mini display port to DVI adapters which worked great, but they burned out after about a year or two. The 15 foot hdmi cables, which claim 50 foot limits, couldn't handle the 15 feet reliably. They allowed the signal to degrade enough that my monitors fell out of sync. They may handle 50 feet for tv, but not a monitor. Thinking it was a video card issue, I contacted XFX, who was fantastic, but before we did anything, I connected some old, shorter cables to test with and found everything was fine. I now use the previously mentioned DVI cables.


I have a custom built box on my desk, which contains a powered USB 3 hub for the desktop and two esata ports (desktop and file server). It also contains power and hdd lights and power switches for 4 systems in my basement as well as a power switch to turn on and off my modem and router remotely. Makes things much easier. I plug in a usb dvd rom when necessary, which is about once a year. I also have a powered USB 2.0 hub under the desk connected to the desktop (as opposed to the USB 3.0 hub), which is where my keyboard and mouse connect, this ensures a clean signal for them regardless of what I connect to the USB 3.0 hub.

The nice thing about this setup is that the computer sits in a cool room (basement), where I can't see or hear it. It also keeps from having to run the air conditioner as much upstairs. It's actually saved me money in the long run, I use less electricity and there is no need to invest in quieter fans or power supplies.

I guess PS/2 over USB when it comes to keyboards can also boil down to one's preferences. Though I still somewhat stick by my initial reasonings of using PS/2 where possible (and ideally if both the keyboard as well as the computer natively has PS/2 connections). Prior to USB3.0 virtually all the older USB specifications had protocol overhead. Naturally such cases are irrelevant if one has their keyboards and mouse (both using USB) are plugged directly to the motherboard via the rear or through the USB headers. However in the cases of USB hubs there are lots more reasons that can appear.

Say for instance I have USB2.0 (I actually do but anyway) but an extremely fast/powerful machine, I decide to hook up all my external hard drives (mechanical 7200rpm with huge capacities) via a single USB hub and take the machine with the setup more or less to a LAN party where people share/trade stuff. Now if I were to have say three or four external hard drives plugged into a USB hub and that hub is then connected with to the motherboard via the rear but the USB keyboard and USB mouse shares the same single USB hub as those three or four external hard drives. Now at the moment when there are lots of activities going on the LAN connection due to data being transreceived and hence because the destination of the data has to go to all these individually plugged USB hard drives on the same USB hub along with USB keyboard and USB mouse. The moment I start typing away like hell on a keyboard, say for instance I could type more than 120 wpm on a sustained rate, I am fairly sure with USB2.0 and with that many hard drives all transreceiving on the same USB hub there will be compromises that has to be made. It from there on really go either way. Either the inputs from keyboard would be delayed (by a small fraction compared to no loads) and/or there would be a slight drop in throughputs between active external hard disks that are all transreceiving data. I believe this would be a likely scenario that would happen and would hence may see for instance one needs to either use other USB ports, USB hubs or get expansion cards to alleviate the issue.

On the same case, had I been using a proper PS/2 keyboard with a computer that would ideally natively have PS/2 port the lag (if any) coming from all the external hard drives that are transreceiving data at that particular moment, I could be somewhat reassured the lag would not be because of PS/2 issue but moreso would have been USB2.0's limitation or machine limitation via CPU for instance. Therefore any lags from PS/2 would have been very minimal (as opposed to say USB2.0) because again the only devices that really uses PS/2 connection on virtually any generic PC are keyboards and mouse only.

Keeping in mind that most basic LAN connections are gigabit so topping out a gigabit LAN with a few external hard drives hooked up via one USB hub on USB2.0 base is unlikely. It is also somewhat understandably that because older USB implementations had overheads, so too would the CPU usage likely be spiked up as well for instance. This was also where I stated that if I were to run a powerful modern machine, besides a powerful modern machine is usually a pre-requisite for LAN parties as most people are usually gamers.

The case in itself maybe a little exaggerated but in theory this is also a possible scenario of where one may face issues with USB keyboards and/or mice. USB3.0 implementation have already addressed the issue in protocol overheads and have thus again raised the bar on the maximum theoretical throughput of the said technology which would most likely see this case rather moot.

Having covered USB2.0 speed issues, USB as far as I know of even now can still suffer power issues. For instance, if I were to use a regular unpowered (or bus powered) seven ports USB hub and attach, say three or four 2.5" mechanical hard drives along with USB keyboard and/or USB mouse one is likely to see either the keyboard gets unpowered or the mouse and/or at least one of the 2.5" mechanical hard drives. Bus powered USB hubs can only go as far up as 0.5A according to wikipedia (5A when charging but I guess charging alone only). Even though USB could go right up to 0.9A, having more than say two 2.5" external hard drives plugged onto a bus powered USB hub along with USB keyboard and/or mouse it is unlikely to see that the power hungry 2.5" portable hard drives would still remain powered along with the USB keyboard and/or mouse. Even for instance having five 2.5" external hard drives plugged into a self powered seven port USB hub leaving two spare USB ports for USB keyboard and USB mouse, it may still leave certain peripherals in the very least power starved.

The same case would never happen if the keyboard and/or mouse is PS/2 powered as again the only main peripherals on the PC that uses such port are keyboards and mice alone. So the issue is nullified as it is irrelevant.

Again a bit of exaggeration being put forth into play but it maybe a possible scenario. One could probably also extrapolate such scenarios by having USB hubs for instance daisy chained.

I am not trying to grill you here over it neither am I here to proclaim PS/2's superiority for all scenarios. However PS/2 still has it's place apart from lacking ports and/or using old legacy keyboards in my humble opinion. 

Running long cables and having the main machine far and away does have its benefits undoubtably but running long cables alone has a bit of an issue. Partly because of the data that needs to transfer over a long cable (but that is highly irrelevant so long as one uses a compliant cable that basically complies with the standards. For instance, regular (8P8C) network cables generally complies with EIA/TIA 568 standards) but also because there potential issues with interferences.

Definitely having computer(s) in basement and running cables to where your other peripherals are has its benefits without a doubt. I guess one of the potential downsides is that if in the future you want to upgrade the machines for instance that would require travelling into the basement.

Sources:

• http://en.wikipedia.org/wiki/USB
• http://en.wikipedia.org/wiki/Hard_disk_drive
• http://en.wikipedia.org/wiki/USB_hub
• http://en.wikipedia.org/wiki/TIA/EIA-568
• http://en.wikipedia.org/wiki/Coaxial_cable#Interference_and_troubleshooting

[Betty]

I remap a lot of keys on my keyboards to come as close as I can to the HHKB layout, except of course on the HHKB itself.
So I need lsusb to detect the keyboard and to let the cron job do the work. Otherwise with PS/2 I would have to do that by myself
everytime I change the keyboard.
But this is the only reason and I never recognized any improvement over PS/2 except NKRO.

I was looking at ways to find how to get all the keys and shortcuts working with KDE4 and my HHKB Pro JP. As I started broadening my search (first by looking at Japanese websites for a few reasons) I came stumbling across a really nifty program which will not only detect USB keyboard but also the PS/2 keyboard. The command is:

Code: [Select]

xinput --listRight now with my HHKB Pro JP plugged in via USB port (and placed physically in the background with keyboard roof on) and using APC Clicker F-21 via DIN -> PS/2 adapter which is then plugged into the back of my machine with a proper PS/2 port the result of my xinput --list shows this:

Code: [Select]

⎡ Virtual core pointer                          id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ Logitech USB-PS/2 Optical Mouse           id=8    [slave  pointer  (2)]
⎣ Virtual core keyboard                         id=3    [master keyboard (2)]
    ↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
    ↳ Power Button                              id=6    [slave  keyboard (3)]
    ↳ Power Button                              id=7    [slave  keyboard (3)]
    ↳ AT Translated Set 2 keyboard              id=9    [slave  keyboard (3)]
    ↳ PFU Limited  HHKB Professional JP         id=10   [slave  keyboard (3)]
I thought I might as well give you the heads up with this nifty program in favour of lsusb when it comes to dealing with PS/2 keyboards. You can see my APC Clicker F-21 keyboard is being noted as "AT Translated Set 2 keyboard". I do not know if all PS/2 keyboards will appear like this, or would only the DIN -> PS/2 keyboards would appear like this or whatever but at least with xinput I could not only see my keyboards and mouse plugged in but for the USB based devices I could easily see their vendor and product names being mentioned. DIN and PS/2 keyboards for instance lacks "ID sending" scheme so it may most likely appear as some generic keyboard as you can see here.

Apparently the article also went on that one can also disable/enable inputs as well which was quite interesting. Though unrelated.

I did not get my keyboard shortcuts to work but that again is another story. xmodmap clearly is doing its job but KDE4 isn't.

Source (Japanese only):

• http://qiita.com/ka_/items/47f12dd17780e33155a7

Thanks, I didn't knew this nifty little tool, but it seems to give all keyboards connected via PS/2 the same identifier:

Virtual core keyboard                         id=3    [master keyboard (2)]
        Reporting 1 classes:
                Class originated from: 8. Type: XIKeyClass
                Keycodes supported: 248

    ↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
        Reporting 1 classes:
                Class originated from: 5. Type: XIKeyClass
                Keycodes supported: 248

    ↳ Power Button                              id=6    [slave  keyboard (3)]
        Reporting 1 classes:
                Class originated from: 6. Type: XIKeyClass
                Keycodes supported: 248

    ↳ Power Button                              id=7    [slave  keyboard (3)]
        Reporting 1 classes:
                Class originated from: 7. Type: XIKeyClass
                Keycodes supported: 248

    ↳ ACPI Virtual Keyboard Device              id=11   [slave  keyboard (3)]
        Reporting 1 classes:
                Class originated from: 11. Type: XIKeyClass
                Keycodes supported: 248

    ↳ AT Translated Set 2 keyboard              id=8    [slave  keyboard (3)]
        Reporting 1 classes:
                Class originated from: 8. Type: XIKeyClass
                Keycodes supported: 248

[\quote]
until now, I don't have any keyboard which has a PS/2 plug. But since I'm looking for a SSK I will have to deal with that problem one day (hopefully). 
But at least xinput gives you a more intuitive identification of a keyboard than the 8 digit ID from lsusb.

Even if it is a bit OT, what are your problems with the HHKB on KDE?

[tuxsavvy]

I remap a lot of keys on my keyboards to come as close as I can to the HHKB layout, except of course on the HHKB itself.
So I need lsusb to detect the keyboard and to let the cron job do the work. Otherwise with PS/2 I would have to do that by myself
everytime I change the keyboard.
But this is the only reason and I never recognized any improvement over PS/2 except NKRO.

I was looking at ways to find how to get all the keys and shortcuts working with KDE4 and my HHKB Pro JP. As I started broadening my search (first by looking at Japanese websites for a few reasons) I came stumbling across a really nifty program which will not only detect USB keyboard but also the PS/2 keyboard. The command is:

Code: [Select]

xinput --listRight now with my HHKB Pro JP plugged in via USB port (and placed physically in the background with keyboard roof on) and using APC Clicker F-21 via DIN -> PS/2 adapter which is then plugged into the back of my machine with a proper PS/2 port the result of my xinput --list shows this:

Code: [Select]

⎡ Virtual core pointer                          id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ Logitech USB-PS/2 Optical Mouse           id=8    [slave  pointer  (2)]
⎣ Virtual core keyboard                         id=3    [master keyboard (2)]
    ↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
    ↳ Power Button                              id=6    [slave  keyboard (3)]
    ↳ Power Button                              id=7    [slave  keyboard (3)]
    ↳ AT Translated Set 2 keyboard              id=9    [slave  keyboard (3)]
    ↳ PFU Limited  HHKB Professional JP         id=10   [slave  keyboard (3)]
I thought I might as well give you the heads up with this nifty program in favour of lsusb when it comes to dealing with PS/2 keyboards. You can see my APC Clicker F-21 keyboard is being noted as "AT Translated Set 2 keyboard". I do not know if all PS/2 keyboards will appear like this, or would only the DIN -> PS/2 keyboards would appear like this or whatever but at least with xinput I could not only see my keyboards and mouse plugged in but for the USB based devices I could easily see their vendor and product names being mentioned. DIN and PS/2 keyboards for instance lacks "ID sending" scheme so it may most likely appear as some generic keyboard as you can see here.

Apparently the article also went on that one can also disable/enable inputs as well which was quite interesting. Though unrelated.

I did not get my keyboard shortcuts to work but that again is another story. xmodmap clearly is doing its job but KDE4 isn't.

Source (Japanese only):

• http://qiita.com/ka_/items/47f12dd17780e33155a7

Thanks, I didn't knew this nifty little tool, but it seems to give all keyboards connected via PS/2 the same identifier:

Virtual core keyboard                         id=3    [master keyboard (2)]
        Reporting 1 classes:
                Class originated from: 8. Type: XIKeyClass
                Keycodes supported: 248

    ↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
        Reporting 1 classes:
                Class originated from: 5. Type: XIKeyClass
                Keycodes supported: 248

    ↳ Power Button                              id=6    [slave  keyboard (3)]
        Reporting 1 classes:
                Class originated from: 6. Type: XIKeyClass
                Keycodes supported: 248

    ↳ Power Button                              id=7    [slave  keyboard (3)]
        Reporting 1 classes:
                Class originated from: 7. Type: XIKeyClass
                Keycodes supported: 248

    ↳ ACPI Virtual Keyboard Device              id=11   [slave  keyboard (3)]
        Reporting 1 classes:
                Class originated from: 11. Type: XIKeyClass
                Keycodes supported: 248

    ↳ AT Translated Set 2 keyboard              id=8    [slave  keyboard (3)]
        Reporting 1 classes:
                Class originated from: 8. Type: XIKeyClass
                Keycodes supported: 248

until now, I don't have any keyboard which has a PS/2 plug. But since I'm looking for a SSK I will have to deal with that problem one day (hopefully). 
But at least xinput gives you a more intuitive identification of a keyboard than the 8 digit ID from lsusb.

Even if it is a bit OT, what are your problems with the HHKB on KDE?

No worries, we all learn something new everyday. 

Mind you the inputs listed aren't necessarily all keyboard inputs. Stuff like Power button are probably the physical buttons on the PC itself. Normal PC would only have one PS/2 port (or two) but according to your xinput --list output it seems like your keyboard is reporting the same ID name as mine.

Yeah I personally find switching to compact keyboard layout (anything less than TKL) is where keyboard remapping can really benefit one. Then of course there are issues with using international layouts (like JIS in my case). This is where as HaaTa pointed out to me before xmodmap helps. It is kinda like autohotkey (windows), and keyremap4mac (macintosh) equivalent under linux.

I am not sure how xinput gets the device ID but I bet it will probably be enumerated the same way as how lsusb does and then prints it out in correlation to how I guess it is mapped under X environment.

My problem with HHKB on KDE is that the global shortcuts are not working. I have for instance a program called yakuake which is a drop down (floating style) terminal. I absolutely love the program for it's handiness and that it rolls down/up at the press of a button. The shortcut for that is F12. Since putting on HHKB JP and having to reconfig xmodmap several times. F12 no longer works. Even if I were to set the shortcut as F12 again (via letting it detect from keyboard what buttons I press). I have even tried binding the shortcut to other F keys but still no dice.

The same thing for instance, if I were to try switching to one of the vty (via Ctrl+Alt+F{1-6}) it would not work. At times the up arrow under yakuake or my IRC clients (xchat and irssi respectively) does not show whatever I wrote previously for that window/channel. There are a few other minor issues but the majority are as that. I have been suggested by yakuake maintainer to try contacting this other person on #kde IRC channel but it has been extremely hard for me to reach him because of timezones and that he only appears online for an hour or so before disconnecting. Thinking of it now I guess I could probably try memoing him, hopefully he won't mind.

I have also tried mapping my keyboard with KDE's keyboard config tool, and there was no layout specifically for HHKB JP but only HHKB itself. Using that layout is no different to the sitation that I am still facing. So yeah, initially I kept thinking it was xmodmap's fault but as HaaTa pointed out that his keyboards work fine and even his DE/WM (he doesn't run KDE but some other floating WM if I remember correctly). So the issue seems to be KDE's global shortcuts.

[Leslieann]

However in the cases of USB hubs there are lots more reasons that can appear.

Say for instance I have USB2.0 (I actually do but anyway) but an extremely fast/powerful machine, I decide to hook up all my external hard drives (mechanical 7200rpm with huge capacities) via a single USB hub and take the machine with the setup more or less to a LAN party where people share/trade stuff.

~snip~

Forget overhead, there is a much more sinister issue with what you are describing. You still have prioritization, which means a mouse and keyboard would get priority, though for some reason some wireless mice can be disturbed by it, probably due to a lower priority, maybe the system thinks it's a network device. While I have experienced the wireless lag, I don't think I have ever experienced keyboard lag and I do use lots of hubs and USB  (I have 6 hubs in the house and another on the way).

Regardless, there is another issue in regards to your scenario.
Most USB mice and keyboards are still USB 1.0 or 1.1, so, unless you have one of about 4 Usb 2.0 hubs made that had Multi-TT, all of your devices drop to USB 1.0 or 1.1 speeds. I believe only Belkin still makes a USB 2.0  Multi-TT hub (the 7 port F5U237) and they are among the more expensive 2.0 hubs made and not always easy to find. Worse, even if you find one, there is speculation that the newer versions have Multi-TT locked out, my guess is due to how much power and heat they use and generate, I added a heatsinks to one of mine after it got hot enough to discolor the plastic housing. Yes, it gets that hot. The newer one runs warm but not as warm, I suspect age may have played a part in the one getting hotter. It still functions great though.

This is the real reason I use an older 2.0 hub for my mouse and keyboard, and a second 3.0 for my flash drives and hard drive connections. I want as much speed as I can get.

Keeping in mind that most basic LAN connections are gigabit so topping out a gigabit LAN with a few external hard drives hooked up via one USB hub on USB2.0 base is unlikely. It is also somewhat understandably that because older USB implementations had overheads, so too would the CPU usage likely be spiked up as well for instance. This was also where I stated that if I were to run a powerful modern machine, besides a powerful modern machine is usually a pre-requisite for LAN parties as most people are usually gamers.

10/100 is still quite common I see it all the time, though you probably won't on a gaming machine, though gamers could flood a gigabit switch.
Conversely, on a machine like that, USB cpu overhead should be minimal at best (1-2% maybe) and much of that would be drive access anyhow. If not, you should be checking for driver updates. Also, if those transfers are using 20% or more of your resources, your gaming will suffer anyhow.

F.Y.I.
USB 2.0 tops out at half what Gigabit does, and gigabit runs at about 3/4 of what a conventional drive can handle.
Actual transfer speeds you might see on a good system are 40megs* on USB, 110 on Gigabit and 150 on a conventional Sata drive. I average 115 on my network (peaks of 125), but most systems I have tested tend to be hard pressed to even break 100meg at peak.  USB 1, I don't remember the speeds, probably about 1-8megs, when I get knocked down to it, I find an alternate method to transfer the files, it's just too painful.  *These are stated in megabyte, not megabit*

The case in itself maybe a little exaggerated but in theory this is also a possible scenario of where one may face issues with USB keyboards and/or mice. USB3.0 implementation have already addressed the issue in protocol overheads and have thus again raised the bar on the maximum theoretical throughput of the said technology which would most likely see this case rather moot.
 

I get conflicting reports about USB 3.0, about whether everything thing slows or not. One report says none do, meanwhile at least one manufacturer sells a USB 3.0 hub that specifically mentions that it has Multi-TT.  I will have to do some experimentation and find out.
If USB is not multi-TT, then you will still have the same problems.

Having covered USB2.0 speed issues, USB as far as I know of even now can still suffer power issues. For instance, if I were to use a regular unpowered (or bus powered) seven ports USB hub and attach, say three or four 2.5" mechanical hard drives along with USB keyboard and/or USB mouse one is likely to see either the keyboard gets unpowered or the mouse and/or at least one of the 2.5" mechanical hard drives. Bus powered USB hubs can only go as far up as 0.5A according to wikipedia (5A when charging but I guess charging alone only).

~snip~
 

You should never use a bus powered hub and connect ANY drive to it for power. Bus powered hubs are designed for low power devices only. Some laptop drives alone can use .9amps which didn't allow them to even run off an older USB 1.1 port even when directly connected to the mainboard.

USB is “smart” and remember the prioritization...
A few issues with your statement from the start though.

Based on USB specs, a 7 port hub technically should have a 7 amp power supply, however, it doesn't. Most are 2 amp or so, but even those should handle a couple laptop drives and a mouse and keyboard, the latter of which use very little. Why? Because anyone connecting more than 4 drives to be powered from a hub deserve what they get. Even if it works, the speeds would be atrocious, even if you had full USB speeds. Peak USB divided 4 ways, for large data transfer, no thank you.

Anyhow, in the event of an over current, the hub and OS will/should only shutdown the item with the highest draw that puts it over the top. Not everything, and certainly not the mouse or keyboard.

The same case would never happen if the keyboard and/or mouse is PS/2 powered as again the only main peripherals on the PC that uses such port are keyboards and mice alone. So the issue is nullified as it is irrelevant.

I have had devices that used ps2 power to run them, including a webcam, and tv card.

Again a bit of exaggeration being put forth into play but it maybe a possible scenario. One could probably also extrapolate such scenarios by having USB hubs for instance daisy chained.

I am not trying to grill you here over it neither am I here to proclaim PS/2's superiority for all scenarios. However PS/2 still has it's place apart from lacking ports and/or using old legacy keyboards in my humble opinion.   

PS2 is a shell of it's old self.

Some chipsets no longer carry a ps2 system, so you get a daughter chip to run it. They have also removed most of the power it used to get. I know Intel at least considered doing this 5 years ago. IF this is the case, most peoples arguments for PS2 truly goes right out the window.  I can't confirm it, but I've heard that ICH9 dropped native PS2 support, that was the plan from Intel at one time. If they didn't, it wouldn't surprise me if they did by ICH10.


Anyhow, I stand by what I said.
Yes, there are occasions, but they are few and far between.

Definitely having computer(s) in basement and running cables to where your other peripherals are has its benefits without a doubt. I guess one of the potential downsides is that if in the future you want to upgrade the machines for instance that would require travelling into the basement.

I rarely upgrade my systems anymore, we passed the point where it's necessary or beneficial to upgrade every few months.

Besides, there is very little room to upgraded anything that will benefit me. All my systems down there are drool worthy.

[jonathanyu]

I use ps/2.  The reason why I use ps/2 is because if I use usb, there will be some lag.  I know it is strange 

[Linkas]

I have old mouse which has PS/2 plug. I would like to use PS/2 port for my keyboard too but my motherboard has one combo PS/2 slot. Almost every modern motherboard has this combo slot. I think that there will be no PS/2 in computer soon. Manufactures try to cut down cost and space.

[babyface]

If my Ducky had a PS2 cable I would (:

[Melchior]

PS/2 Will always work if the system isn't dead.

USB in DOS? No. (well actually usually yes, but that's because of a BIOS service...)

And indeed its protocol always IS AT Translated Command set 2. Its still an AT Keyboard, just using the PS/2 connector - which IBM made popular with the "Personal System 2" PC.
(Or MB manufacturers did not want to cram Huge DIN5 connectors on the back panels anymore - they were pretty big.)

Also who in their right mind would run DVI/HDMI cables 8+ feet without signal re-drivers!?!
Highspeed transceivers do 'OVERLOAD' if they have too much distance between cable ends !

Strangely enough PS/2 has pretty good long range signal integrity (and its Bi-Directional too!) albeit at very low speeds. And Most older KVM's ARN'T USB - although these days if your data center NEEDs a KVM it isn't modern

[Elrick]

I have old mouse which has PS/2 plug. I would like to use PS/2 port for my keyboard too but my motherboard has one combo PS/2 slot. Almost every modern motherboard has this combo slot. I think that there will be no PS/2 in computer soon. Manufactures try to cut down cost and space.

This company still produces a current motherboard with both of these connectors and here it is;

http://www.asrock.com/mb/AMD/990FX%20Extreme9/

Absolutely brilliant motherboard.  I still don't mind using AMD because I first started using a K6-III  .

Have stuck with PS/2 because it always worked with EVERY Microsoft OS ever made, as well as Linux.  I ignore any motherboard that has no PS/2 ports, sorry but that's how I roll.

[tuxsavvy]

However in the cases of USB hubs there are lots more reasons that can appear.

Say for instance I have USB2.0 (I actually do but anyway) but an extremely fast/powerful machine, I decide to hook up all my external hard drives (mechanical 7200rpm with huge capacities) via a single USB hub and take the machine with the setup more or less to a LAN party where people share/trade stuff.

~snip~

Forget overhead, there is a much more sinister issue with what you are describing. You still have prioritization, which means a mouse and keyboard would get priority, though for some reason some wireless mice can be disturbed by it, probably due to a lower priority, maybe the system thinks it's a network device. While I have experienced the wireless lag, I don't think I have ever experienced keyboard lag and I do use lots of hubs and USB  (I have 6 hubs in the house and another on the way).

Regardless, there is another issue in regards to your scenario.
Most USB mice and keyboards are still USB 1.0 or 1.1, so, unless you have one of about 4 Usb 2.0 hubs made that had Multi-TT, all of your devices drop to USB 1.0 or 1.1 speeds. I believe only Belkin still makes a USB 2.0  Multi-TT hub (the 7 port F5U237) and they are among the more expensive 2.0 hubs made and not always easy to find. Worse, even if you find one, there is speculation that the newer versions have Multi-TT locked out, my guess is due to how much power and heat they use and generate, I added a heatsinks to one of mine after it got hot enough to discolor the plastic housing. Yes, it gets that hot. The newer one runs warm but not as warm, I suspect age may have played a part in the one getting hotter. It still functions great though.

This is the real reason I use an older 2.0 hub for my mouse and keyboard, and a second 3.0 for my flash drives and hard drive connections. I want as much speed as I can get.

There are some points that I do agree with you. Though I was merely extrapolating if one misuses the USB given the fact that there are the likes of USB hubs these days along with the fact  that it has more or less became the defacto standard within computer realm when it comes to external peripheral connectivity. There are some points that I am not too sure personally about such as Multi-TT hub (the 7 port Belkin F5U237) mainly because I have hardly played with many USB hubs.

I would too use USB2.0 for peripherals that does not need all that much bandwidth, notably keyboards, mouse/trackball/touchpad/tablet, etc and keep flash storage drives or generally a multimedia sort of peripheral such as a camera, video camera, etc to a USB3.0 or force it onto another USB port (from motherboard) where possible.

Keeping in mind that most basic LAN connections are gigabit so topping out a gigabit LAN with a few external hard drives hooked up via one USB hub on USB2.0 base is unlikely. It is also somewhat understandably that because older USB implementations had overheads, so too would the CPU usage likely be spiked up as well for instance. This was also where I stated that if I were to run a powerful modern machine, besides a powerful modern machine is usually a pre-requisite for LAN parties as most people are usually gamers.

10/100 is still quite common I see it all the time, though you probably won't on a gaming machine, though gamers could flood a gigabit switch.
Conversely, on a machine like that, USB cpu overhead should be minimal at best (1-2% maybe) and much of that would be drive access anyhow. If not, you should be checking for driver updates. Also, if those transfers are using 20% or more of your resources, your gaming will suffer anyhow.

F.Y.I.
USB 2.0 tops out at half what Gigabit does, and gigabit runs at about 3/4 of what a conventional drive can handle.
Actual transfer speeds you might see on a good system are 40megs* on USB, 110 on Gigabit and 150 on a conventional Sata drive. I average 115 on my network (peaks of 125), but most systems I have tested tend to be hard pressed to even break 100meg at peak.  USB 1, I don't remember the speeds, probably about 1-8megs, when I get knocked down to it, I find an alternate method to transfer the files, it's just too painful.  *These are stated in megabyte, not megabit*

About the CPU usage on USB transfers, again due to extrapolating (and deliberately aiming mainly at USB's "weak points") I thought of comparing a very modern computer system but one is forced to use the likes of USB2.0 as a way to deliberately draw out the issues with USB2.0 in general. I should have somewhat re-affirm my intentions in the case of trying to deliberately reveal USB2.0's weak points even though modern computers would hardly be mainly equipped with USB2.0. Besides one can always get USB3.0 add-on cards. There is one notably exception that I know of but that does not strictly apply to USB alone.

Granted the USB2.0 when fully topped out is roughly half as slow as gigabit connection. That is to not to consider about protocol overheads on either such connectivities. Whilst the standards also did specify that theoretically each of the specified device connectivity speeds could achieve the maximum of x, y, and z (regardless if one uses USB2.0, gigabit or SATA/eSATA). The reality is quite the opposite when for instance one uses mechanical drives. Again I deliberately chose to use conventional (mechanical) hard drives to draw out in basic usages when one deliberately tries to again target USB2.0 for instance the weak points of. These days one can extrapolate such scenarios when for instance hooked up a NAS box via USB full of SATA hard drives that are configured in RAID format. That can easily make use of the theoretical maximum bandwidth that the standards did mention. As pointed by wikipedia, SATA2 is already well ahead in terms of speed comparison against a single mechanical hard drive (even potentially a single SSD but possibly). The case still remains that even with a couple of USB2.0 hard drives hooked up here and there on a single USB hub and say they were all transreceiving data. That could probably hit the limitations of the USB2.0 faster than gigabit LAN would (which again gigabit LAN is virtually twice as fast as USB2.0 and was pushed out onto the market much later than USB2.0.

There are plenty of ways to make use of all the potential theoretical bandwidth of such technologies. One could not only setup RAID but use faster mechanical hard drives (maybe well beyond 7200RPM for instance), hybrid hard drives or SSD. Though for simplicity sake of my debate was again to simply draw out the limitations of USB2.0 on deliberate grounds.

The case in itself maybe a little exaggerated but in theory this is also a possible scenario of where one may face issues with USB keyboards and/or mice. USB3.0 implementation have already addressed the issue in protocol overheads and have thus again raised the bar on the maximum theoretical throughput of the said technology which would most likely see this case rather moot.

I get conflicting reports about USB 3.0, about whether everything thing slows or not. One report says none do, meanwhile at least one manufacturer sells a USB 3.0 hub that specifically mentions that it has Multi-TT.  I will have to do some experimentation and find out.
If USB is not multi-TT, then you will still have the same problems.

I personally do not have much experience on USB3.0 however I have been pointed out the prior revisions (before 3.0) had protocol overheads and that they were addressed to in USB3.0. Besides USB3.0 has much much higher amount of bandwidth available (considering that the design of the USB socket and/or plugs has once again being done to accomodate more on top of the original design whilst retaining backward compatibility).

Having covered USB2.0 speed issues, USB as far as I know of even now can still suffer power issues. For instance, if I were to use a regular unpowered (or bus powered) seven ports USB hub and attach, say three or four 2.5" mechanical hard drives along with USB keyboard and/or USB mouse one is likely to see either the keyboard gets unpowered or the mouse and/or at least one of the 2.5" mechanical hard drives. Bus powered USB hubs can only go as far up as 0.5A according to wikipedia (5A when charging but I guess charging alone only).

~snip~
 

You should never use a bus powered hub and connect ANY drive to it for power. Bus powered hubs are designed for low power devices only. Some laptop drives alone can use .9amps which didn't allow them to even run off an older USB 1.1 port even when directly connected to the mainboard.

USB is “smart” and remember the prioritization...
A few issues with your statement from the start though.

Based on USB specs, a 7 port hub technically should have a 7 amp power supply, however, it doesn't. Most are 2 amp or so, but even those should handle a couple laptop drives and a mouse and keyboard, the latter of which use very little. Why? Because anyone connecting more than 4 drives to be powered from a hub deserve what they get. Even if it works, the speeds would be atrocious, even if you had full USB speeds. Peak USB divided 4 ways, for large data transfer, no thank you.

Anyhow, in the event of an over current, the hub and OS will/should only shutdown the item with the highest draw that puts it over the top. Not everything, and certainly not the mouse or keyboard.

Again a bit of exaggeration being put forth into play but it maybe a possible scenario. One could probably also extrapolate such scenarios by having USB hubs for instance daisy chained.

As wikipedia also stated out that a bus compliant USB hub should be be only four ports not seven ports as that would draw out 500mA with 100mA for each port and 100mA for the controller alone. Inevitably lots of USB hubs are available also as seven port bus powered USB hub (probably because people does not like having an extra wire hanging off the self powered USB hub when there are no other USB peripherals connected. So yeah as stated before I'll reinstate my intentions were to deliberately target at USB2.0 flaws.

Inevitably not all people are that bright. Obviously on tech forums like this it is true that no unwise person would hook up more than two or more 2.5" external (and mechanical) hard disk. This is why I chose the worst possible scenario and exaggerate the issue many folds to not only show the flaws with USB2.0 but to also point out what if there are some unwise people whom does not understand (and may not want to understand) how electronics would work.

The same case would never happen if the keyboard and/or mouse is PS/2 powered as again the only main peripherals on the PC that uses such port are keyboards and mice alone. So the issue is nullified as it is irrelevant.

I have had devices that used ps2 power to run them, including a webcam, and tv card.

When you mention about other devices using PS/2 connector, I was reminded that my family once had an old wacom inspired (or whatever) tablet (brand name was called "Pen Power") which I believe also did feature PS/2 connector. Ironically I never dealt with webcams and/or TV card using PS/2 connectors. Maybe such devices of those times could be compensated for low(er) latencies but given the amount of bandwidth that PS/2 theoretically provides along with the power it makes me wonder what the performances would be like.

I am not trying to grill you here over it neither am I here to proclaim PS/2's superiority for all scenarios. However PS/2 still has it's place apart from lacking ports and/or using old legacy keyboards in my humble opinion.   

PS2 is a shell of it's old self.

Some chipsets no longer carry a ps2 system, so you get a daughter chip to run it. They have also removed most of the power it used to get. I know Intel at least considered doing this 5 years ago. IF this is the case, most peoples arguments for PS2 truly goes right out the window.  I can't confirm it, but I've heard that ICH9 dropped native PS2 support, that was the plan from Intel at one time. If they didn't, it wouldn't surprise me if they did by ICH10.


Anyhow, I stand by what I said.
Yes, there are occasions, but they are few and far between.

Yeah when USB became a hit with all the various gadgeteries (of its time) started taking advantage of the higher bandwidth as well as the power it provided (plus the design of the USB bulkhead/plug looks more rugged as opposed to incorrectly forcing PS/2 plug into say a S-Video socket thereby bending the pins inside that poor PS/2 plug) It started spelling doom for PS/2 as it has more or less happened fast forwarding to 2013.

Inevitably PS/2 like many other old fashioned connectors such as those old school parallel ports and serial (DB9) ports will be relegated as the ancient times of historic computing. Granted time would never stand still and that there will always be something new to "cannibalise" whatever seems to be the norm of its era. PS/2 is still nonetheless interesting for its day and age.

I personally have no qualms with USB, however as new connectors take place of what was once the norm would sort of encourage headaches/challenges for those who still prefer to hang onto legacy/relic devices. Typing here on an old (but refurbished) keyboard which still features a DIN plug and requiring conversion to PS/2 the keyboard still is fun to use for instance. I would sort of hate to deal with converting it to USB when also such adapters for instance are not the ideal solution. I have had some really cheap PS/2 to USB adapters which either favours the mouse (when PS/2 mouse plugged in on its own PS/2 plug from the adapter) or the keyboard would fail to work in some instances. That particular instance gave me a bad impression of PS2 to USB adapters and that if adapters continue to be like that it will be a headache/challenge for me to get a controller board capable of natively transferring key presses through to USB. Of course countless others here for instance has already done it.

Definitely having computer(s) in basement and running cables to where your other peripherals are has its benefits without a doubt. I guess one of the potential downsides is that if in the future you want to upgrade the machines for instance that would require travelling into the basement.

I rarely upgrade my systems anymore, we passed the point where it's necessary or beneficial to upgrade every few months.

Besides, there is very little room to upgraded anything that will benefit me. All my systems down there are drool worthy.

Sounds like you are content with your setup. I also don't upgrade as much but I guess I was sort of pointing the negatives of running long cables for instance.

Sources:

• http://en.wikipedia.org/wiki/List_of_device_bandwidths
• http://answers.yahoo.com/question/index?qid=20100929064746AASTPsw

This bit of debate is getting a bit big even though I guess both of us are making the most use out of a single forum posts. I almost lost track when I took a different approach in responding.  )

[Keytrun]

Wow - HUGE walls of text.

I read a little bit of it, but you all keep talking about plugging things into a USB hub and having bandwidth issues. Can I just get a simple yes or no here? I have my mouse, keyboard, nvidia 3d receiver, and microphone plugged directly into the motherboard's USB - and occasionally an external drive. Would having the keyboard usb / ps2 make any difference whatsoever in that setup?

[tuxsavvy]

Wow - HUGE walls of text.

I read a little bit of it, but you all keep talking about plugging things into a USB hub and having bandwidth issues. Can I just get a simple yes or no here? I have my mouse, keyboard, nvidia 3d receiver, and microphone plugged directly into the motherboard's USB - and occasionally an external drive. Would having the keyboard usb / ps2 make any difference whatsoever in that setup?

The plugging things into USB hub and having bandwidth issues were me attacking on USB's weakness (although specifically at 2.0 specification). Not that I loathe USB but because it is too commonly used that people may get wrong conceptions of USB usage.

Your answer would be no. If they are all plugged to motherboard's USB than having PS/2 connectors won't make that much more difference. If your motherboard supports PS/2 connectors and you have legacy keyboards maybe you can use the PS/2 connector for legacy keyboads. Otherwise conversion from USB -> PS/2 isn't really going to get you much benefit let alone with motherboards that natively do not have PS/2 connectors.

[fohat.digs]

My Gigabyte motherboard is happier when the keyboard is plugged into the PS/2 port than it is with the USB port.