Author Topic: USB or PS2 (Read 4770 times)

OverSky · « **on:** Wed, 17 June 2009, 20:28:45 »

Can anyone give me as much information as possible about what benefits each connections method offers?

I know PS2 can provide infinite key rollover while USB caps at 6 but what about latency or other factors?

Any links about the question would be helpful, thanks!

dfrey · « **Reply #1 on:** Wed, 17 June 2009, 20:34:53 »

One benefit of USB is that you can plug in and unplug the keyboard and still expect it to behave correctly.

o2dazone · « **Reply #2 on:** Wed, 17 June 2009, 20:38:44 »

When going standby / hibernate on Windows machines, power is still supplied to the ps/2 port, allowing you to wake it up via the keyboard.

ps/2 also doesn't have plug n play. You must boot into Windows with ps/2 plugged in. After it's booted you can unplug it and plug it back in, just as long as it's to the same port.

OverSky · « **Reply #3 on:** Fri, 19 June 2009, 18:42:15 »

Ok I'm gonna answer my own question and say that PS2 is better for performance..

I couldn't get under 6ms lag time using USB and got 3ms using PS2.
Also infinite rollover is pretty fun.

Hope this helped someone.

ch_123 · « **Reply #4 on:** Fri, 19 June 2009, 18:51:48 »

I'd go for PS/2. Leaving aside the NKRO etc, why waste a USB port when you can use something else? And PS/2 is pretty hotpluggable... havent had many problems so far!

mike2h · « **Reply #5 on:** Wed, 02 September 2009, 17:04:58 »

fyi the razer tarantula is a usb keyboard that is fully nkro. poor build quality tho.
question does ps/2 offer more current than usb? looks like im getting a deck legend & want to make sure its getting sufficient power & doesnt tax the usb port- have seen em go bad.
if it is truly non issue then i wont worry about it.

ch_123 · « **Reply #6 on:** Wed, 02 September 2009, 17:15:15 »

Quote from: mike2h;114110

fyi the razer tarantula is a usb keyboard that is fully nkro. poor build quality tho.

Are you sure? (i.e. have you done the proper NKRO tests on the site, manufacturer claims rarely count for anything) Does it require a special driver to support NKRO?

[/QUOTE]question does ps/2 offer more current than usb? looks like im getting a deck legend & want to make sure its getting sufficient power & doesnt tax the usb port- have seen em go bad.
if it is truly non issue then i wont worry about it.[/QUOTE]

USB supplies almost twice the power (500mA vs 275mA) but that's not going to be an issue unless you have a really low quality motherboard, or a really low quality keyboard that doesn't meet specification. Does Deck even support PS/2 on their boards?

mike2h · « **Reply #7 on:** Wed, 02 September 2009, 18:18:51 »

well, i was wrong about the tarantula, it has anti- ghosting for up to 10 keys- not full nkro. sorry about that.
as far as deck goes, when you order a kb you choose wether you want it to be usb or ps/2.

and thank you for that bit of info:)

Hak Foo · « **Reply #8 on:** Thu, 03 September 2009, 01:18:45 »

I've gone from PS/2 to PS/2->USB to native USB, because I know the day is coming when I won't get a proper PS/2 port on the board.

My previous board (Asus M3A78) had only a PS/2 keyboard, not mouse.

It's also nice when some schmuck brings in a laptop (or worse, a MacBook) and expects you to type.

quadibloc · « **Reply #9 on:** Thu, 03 September 2009, 09:13:49 »

I would be inclined to favor PS/2, on the grounds that it doesn't use up a perfectly good USB port, and it would work on older computers. The fact that USB is limited to 6-key rollover would not have affected my decision much, and I don't use hibernate or standby since too much software is not compatible with those modes.

But newer computers may eventually be "legacy-free" and not support a PS/2 keyboard port. There's the safety issue of not having to worry about blowing the motherboard if the connector is jiggled.

And, at least potentially, there could be a USB port on the USB keyboard to plug the mouse into, following what Apple did back with its earlier ADB port, which nicely reduces cord clutter. That, to me, is the biggest argument for USB.

So it's very much a personal choice, based on the factors people have cited here.

Since my favorite type of keyboard among the keyboards I own is the Model M, in choosing a computer I would tend to make sure it has a PS/2 keyboard port, but that isn't the same thing as choosing the type of interface when buying a new keyboard.

InSanCen · « **Reply #10 on:** Thu, 03 September 2009, 10:39:34 »

I like that Idea... but I would go for the Confusion factor, and use Cryllic Keycaps. Infact, I may just do that to my fullsize M that I am replacing the SDL connection on.

It does get dragged to LAN parties (UT fests usually)... people who don't know me laugh at the M, and point to their beloved Logitech's... Until I frag them everywhere, then proceed to critique their boards USB boards with "limited" NKRO and no feeling apart from "squishiness" ;-) they usually figure out at that point why people were laughing at them when they ripped on the 'board.

itlnstln · « **Reply #11 on:** Thu, 03 September 2009, 10:51:16 »

I usually use PS2 when I can as I have some compatibility/usage issues in the past using a USB keyboard outside of an OS.

I say that, but in actuality, I have been swapping my 'boards out using USB a lot lately since I haven't been doing any reinstalls or such of late. That, and I don't have any NKRO keyboards where using PS2 would provide much of an advatage. I would also use PS2 if I didn't have enough USB ports.

Special K · « **Reply #12 on:** Thu, 03 September 2009, 12:15:33 »

Quote from: o2dazone;97249

When going standby / hibernate on Windows machines, power is still supplied to the ps/2 port, allowing you to wake it up via the keyboard.

ps/2 also doesn't have plug n play. You must boot into Windows with ps/2 plugged in. After it's booted you can unplug it and plug it back in, just as long as it's to the same port.

My motherboard has an option to allow a USB keyboard to bring the computer out of sleep mode. I'm not sure if this is a standard feature or not.

Special K · « **Reply #13 on:** Thu, 03 September 2009, 12:17:06 »

Quote from: ch_123;97768

I'd go for PS/2. Leaving aside the NKRO etc, why waste a USB port when you can use something else? And PS/2 is pretty hotpluggable... havent had many problems so far!

Isn't there a risk that the pins don't get connected in the correct order and the port gets fried? I remember reading on here that USB ports are designed such that certain pins will physically make contact before others, which guarantees correct operation every time?

Special K · « **Reply #14 on:** Thu, 03 September 2009, 12:26:02 »

Quote from: mike2h;114160

well, i was wrong about the tarantula, it has anti- ghosting for up to 10 keys- not full nkro. sorry about that.
as far as deck goes, when you order a kb you choose wether you want it to be usb or ps/2.

and thank you for that bit of info:)

Do you own one? I'd still be curious to see whether or not it passes the rollover test here:

http://random.xem.us/rollover.html

Special K · « **Reply #15 on:** Thu, 03 September 2009, 12:27:45 »

Quote from: quadibloc;114353

Since my favorite type of keyboard among the keyboards I own is the Model M, in choosing a computer I would tend to make sure it has a PS/2 keyboard port, but that isn't the same thing as choosing the type of interface when buying a new keyboard.

You can always get a blue cube (or 2, or 3) to convert your PS/2 keyboards into USB:

http://www.cyberguys.com/product-details/?productid=4850

timw4mail · « **Reply #16 on:** Thu, 03 September 2009, 12:58:34 »

If it weren't for the fact that I have two AT connector keyboards that I regularly use, and the Model F draws too much power to function on the PS/2 port of my computer, I would just use PS/2, but the fact is that rollover has never been an issue for me.

Out of all my keyboards, the only USB one is my Scorpius M10, sad isn't it?

timw4mail · « **Reply #17 on:** Thu, 03 September 2009, 14:31:52 »

Quote from: ripster;114475

Could you go over that again. The Model F draws a lot of power? Does that mean you have to use a PS/2 to USB adapter with it?

An AT to PS/2 adapter, and then a PS/2 to USB adapter, yes.

JBert · « **Reply #18 on:** Thu, 03 September 2009, 14:53:02 »

Quote from: itlnstln;114381

I usually use PS2 when I can as I have some compatibility/usage issues in the past using a USB keyboard outside of an OS.

If so, it could either be that the BIOS or keyboard did not support the USB HID boot protocol or had some flaws in it.

Either one is unlikely though for modern/quality hardware. Maybe some faulty connection?

itlnstln · « **Reply #19 on:** Thu, 03 September 2009, 15:08:59 »

Quote from: JBert;114481

If so, it could either be that the BIOS or keyboard did not support the USB HID boot protocol or had some flaws in it.

Either one is unlikely though for modern/quality hardware. Maybe some faulty connection?

You assume I have modern/quality hardware. I have an old Athlon 64 (socket 939) setup on a POS AsRock mobo. I think I am going to replace it with an Ion setup.

I don't use my home computer much.

itlnstln · « **Reply #20 on:** Thu, 03 September 2009, 15:13:10 »

Now that I think about it, I might use the ion for a HTPC setup and use my work laptop as my home PC. Right now, I am using Windows 7 on my laptop and using the WMC functionality to stream video from my main rig to the theater. An Ion setup would be better for that since my lappy has Intel integrated graphics. I would then get a NAS, and put all media on it.

mike2h · « **Reply #21 on:** Thu, 03 September 2009, 15:53:02 »

Quote from: Special K;114425

Do you own one? I'd still be curious to see whether or not it passes the rollover test here:

http://random.xem.us/rollover.html

i do have one, but has it failed just over a month after warranty was up no real way to test it. they still make the claim at their website- http://www.razerzone.com/gaming-keyboards/razer-tarantula so i assume that it hasnt been de-bunked since it came out about 16 mths ago.
they also claim anti-ghosting for the 'gaming cluster' on one of their cheaper kb. not sure if they mean WASD or what.. ifit was just WASD it would be a meaningles cliam so i assume it is 10 key to.
sorry i couldnt test that for u, curious myself. wished i would have known about that a few months ago.

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Author Topic: USB or PS2 (Read 4770 times)