Author Topic: [6gv2] (Read 17669 times)

zhuak1 · « **on:** Sun, 31 October 2010, 19:30:16 »

Guys. I play cs and i have this keyboard but it seems that he lags! im using USB.. should i use ps2?

Arc'xer · « **Reply #1 on:** Sun, 31 October 2010, 19:41:19 »

If you want to use PS/2 go right ahead it's an option either way to have a direct interruption of the CPU.

But if it lags then it should be another problem and not a port issue. It's the game's fault, unless the keyboard is damaged in some way.

zhuak1 · « **Reply #2 on:** Sun, 31 October 2010, 19:53:55 »

i dont think its a keyboard problem but something is wrong, im not so fast pressing the buttons or something like that, "straf'ing" in 1.6 like pressing A and D too fast the key seems to "LAG"!

Rajagra · « **Reply #3 on:** Sun, 31 October 2010, 21:34:54 »

Use Aqua's Key Test. You should be able to tell from this if your keyboard is responding as it should.

If PS/2 is noticably faster than USB connection, you probably have a faulty peripheral or controller on the way out.

zhuak1 · « **Reply #4 on:** Sun, 31 October 2010, 21:39:51 »

Didnt try out ps2 but i thing theres a little delay on this.

And rajagra, when i download the file it doesnt open an .exe, its .exe-t file cant open it.

yes, maybe its my MoBo or usb ports problem. Because i cant get stable 500hz on my mouse, it gives me 450-550 and sometimes 1500 or 1900 or wtv. cant get stable values from 499 500 like i've had before i get this new PC (P5Q PRO TURBO mobo).

I've an 1.1 Zowie by the way

zhuak1 · « **Reply #5 on:** Sun, 31 October 2010, 21:42:37 »

Ok, i've downloaded the test but how can i see if i have a delay? Btw, my "Win" left to space key isnt working

Rajagra · « **Reply #6 on:** Sun, 31 October 2010, 22:18:19 »

Assuming you have a fairly recent gaming PC, the key test program should respond instantly as you press and release each key. Hammer away on them and see if it feels right. You shouldn't sense any lag. I'm on an old Athlon 64X2 4200+ machine right now and it shows no lag.

And the 6GV2 doesn't have a left Windows key. You won't catch me there! :smile:

aegrotatio · « **Reply #7 on:** Sun, 31 October 2010, 22:23:15 »

The only lag I've noticed is when I moved from CRT monitors to LCD monitors.
Oh, and only wireless keyboards have lag. USB and PS/2 are just right. Check your settings or get a new 'pooter.

Rajagra · « **Reply #8 on:** Sun, 31 October 2010, 23:23:34 »

Maybe try disabling legacy usb support in the BIOS?

How are you testing the speed? dx_mouse_timer_dialog.exe seems good. Available here for example.

Zen · « **Reply #9 on:** Mon, 01 November 2010, 12:15:16 »

I have the same keyboard and also play cs :
YES, you should use PS/2, it does "lag" over USB .
ALL keyboards "lag" over USB, most people probably won't notice
but gamers who are used to the smooth "gliding" feel will .

Fwiffo · « **Reply #10 on:** Mon, 01 November 2010, 12:58:25 »

A keyboard hooked up through PS/2 will have more air and presence with fuller bass and more dynamic mids.

Zen · « **Reply #11 on:** Mon, 01 November 2010, 13:04:02 »

"Lag" is probably not the right word to use..
It's like the game reacts instantly/simultaneously to any input over PS/2,
making the mouse and keyboard kinda "disappear", over USB you kinda
notice (or "feel") that millisecond where nothing happens.

Not all people notice it, a bit like how some people simply can't see or feel any difference between a CRT-monitor
running 60Hz and one running 100+ ..

Quote

A keyboard hooked up through PS/2 will have more air and presence with fuller bass and more dynamic mids.

Only if the cables have been cryo-frozen and coated with linseed-oil

zhuak1 · « **Reply #12 on:** Mon, 01 November 2010, 14:27:39 »

So.. i should use Ps2 guys?

Maybe its just placebo or ..not. And about the aqua key test.. cant understand. About mouse HZ, i use mouse rate checker and i dont get stable 500hz.

Fwiffo · « **Reply #13 on:** Mon, 01 November 2010, 14:58:46 »

I don't think anyone has demonstrated that they can actually tell the difference in responsiveness between USB and PS/2, which is why I made the comparison to audiophile nonsense. I don't even know if anyone has demonstrated that they can even measure the difference in a real-world situation (i.e. a computer with an operating system).

It would easy to do a double-blind ABX test. Hook up two identical keyboards, one though USB, the other through PS/2 and have someone try to identify which is which without looking at the connections.

Quote from: zhuak1;241191

About mouse HZ, i use mouse rate checker and i dont get stable 500hz.

It's almost certainly just an artifact of the way it's being measured. Unless your mouse is malfunctioning in a noticeable way, don't worry about it.

itlnstln · « **Reply #14 on:** Mon, 01 November 2010, 15:05:07 »

I can't tell the difference in just typing between PS/2 and USB. It would seem to me that if you could notice lag using a keyboard, you probably have other, worse problems.

zhuak1 · « **Reply #15 on:** Mon, 01 November 2010, 15:07:29 »

just as..?

Rajagra · « **Reply #16 on:** Mon, 01 November 2010, 19:23:15 »

Let's take a step back. Did you first notice this lag when you changed the keyboard, or got the new motherboard? Are you using the same screen?

If you are sensitive to delays of a few ms, as some gamers say they are, it is entirely possible you are picking up on normal keyboard response time. We've measured internal key matrix scan times between 2.6ms and 10ms, but this may be added to by debouncing algorithms etc. This delay can't be overcome by any interface, though they may add an additional delay on top.

I can't help but feel this is rather academic for online gaming, where latency as low as 10ms is rare, and 50-100ms is pretty good.

CodeChef · « **Reply #17 on:** Mon, 01 November 2010, 20:27:22 »

Hey, what it seems to be is a phenomenon called rotational velocidensity. You see, newer hard drives have a lower rotational velocidensity, and it in fact affects every part of the computer. Even if your computer is only a year or two old, it can be affected by rotational velocidensity. The solution is to replace all the transistors on your motherboard with vacuum tubes. You see, tubes "fatten" up the signal. Because tubes are older than computers, they are not affected by velocidensity. Tubes were invented before computers were widely in use, and they also have no moving parts. The warm glow and fat tone of the tubes should alleviate any problems you might have. Be sure to order 12AX7 tubes for transistors located on the top of the motherboard (the side with the CPU, expansion slots, etc.) and 6V6 or 5881 tubes for the underside.

Hope this helps!

erricrice · « **Reply #18 on:** Mon, 01 November 2010, 20:49:46 »

zhuak1 · « **Reply #19 on:** Mon, 01 November 2010, 20:52:25 »

Thanks for your help. Im not a computer "genius", but if that is true, this is happening long time ago before i switch computer. Since i bought this one i've switched like 50 times my mouses. So.. you mean that this is a common problem?

CodeChef · « **Reply #20 on:** Mon, 01 November 2010, 21:31:05 »

Dude, I was joking. There is no such thing as rotational velocidensity. Tubes would do nothing for your computer. I really have no idea what's wrong or how to help you. Consider yourself trolled

msiegel · « **Reply #21 on:** Mon, 01 November 2010, 21:35:53 »

audiophile.

muchadoaboutnothing · « **Reply #22 on:** Mon, 01 November 2010, 22:13:26 »

Stealing jokes from reddit now, are we?

zhuak1 · « **Reply #23 on:** Mon, 01 November 2010, 22:55:37 »

Im serious guys. ill give you an exact example.

I move the mouse from the beggining to the end of the pad
if i do it 1 time, 2 times, 3 times its normal and the 4th its like i have acceleration. ive tried mousefix the problem still in there. Maybe its that "1900hz" that sometimes shows me on mouse rate checker that does this?

Fwiffo · « **Reply #24 on:** Mon, 01 November 2010, 23:20:25 »

It's not likely to be anything to do with PS/2 vs. USB. I would start with your general computer diagnostics; start by checking for viruses, spyware, etc. that might be causing you performance problems. If you do suspect there is something wrong with the keyboard or mouse, try plugging them into a different computer and see if they perform the same way.

AvengeR · « **Reply #25 on:** Tue, 02 November 2010, 07:50:30 »

It could be a motherboard issue because of abusing usb ports.

I've encountered some issues with new motherboards (especially laptops) when using mouses at 500hz plus other things at the same time, for example wireless devices or "gaming products" that force 1000hz (can't be a good thing to use the power of 8 usb ports in only a keyboard or a mouse).

try ps/2 for your keyboard, and unplugging some other things as well.

Also your ime1.1 should get stable 500hz. I've not tried zowie products but it's the same sensor from wmo, regular ime1.1, ime3.0 and blue optical (1.1, from 2001 I think).
edit: the proper way to test it is to move your mouse fast and in circles in the mouse rate checker program. It's obvious but it's always worth mentioning.

zefrer · « **Reply #26 on:** Tue, 02 November 2010, 08:01:47 »

Quote from: zhuak1;241421

Im serious guys. ill give you an exact example.

I move the mouse from the beggining to the end of the pad
if i do it 1 time, 2 times, 3 times its normal and the 4th its like i have acceleration. ive tried mousefix the problem still in there. Maybe its that "1900hz" that sometimes shows me on mouse rate checker that does this?

I actually understand what you mean (shock!). If it is what I think it is then it's not a hardware problem at all but something is running that causes your PC to 'stall' or lock-up for a few ms. Then it starts responding again. You see a higher Hz rating in the program because of the lock up causing mouse polls to be queued up and reported all at once when it starts responding again.

I would start with a new, clean OS install somewhere new (do not re-install over your old one..). Install graphics/input drivers and nothing else and test again.

Rajagra · « **Reply #27 on:** Tue, 02 November 2010, 08:08:26 »

I think USB's flakiness has been tamed over the years, but never quite gone away. I'm constantly grateful (and amazed) when it does work perfectly.

zefrer · « **Reply #28 on:** Tue, 02 November 2010, 08:18:47 »

Quote from: Rajagra;241369

I can't help but feel this is rather academic for online gaming, where latency as low as 10ms is rare, and 50-100ms is pretty good.

I'll have to disagree with you there Raj. For online FPS a good ping is 20-30ms. However, playing with 50ms is a lot different than 30ms and most people wouldn't play seriously with anything over 70ms. It's not a linear '40ms is twice as bad as 20ms' kind of thing. The reasons for this are to do with the game itself rather than the ping and how each weapon works with the network code and with higher ping times.

And yes, a 2-5ms _input_ delay on top of a 30ms ping is instantly noticeable to anyone that spends a few hours a week playing FPS games.

zhuak1 · « **Reply #29 on:** Tue, 02 November 2010, 08:47:22 »

I've installed OS like 100 times, nothing fixs. Used 2 pcs too. one asus p5p77 LX and now p5q pro turbo.

Ill switch boards, ill get and MSI sck 775. maybe its just asus fault. Its unplayable.

For you guys should i get an death adder? its the only mouse i havent tried already..

zefrer · « **Reply #30 on:** Tue, 02 November 2010, 08:50:33 »

Maybe you should find what the problem really is first before buying yet more hardware that probably won't do anything/isn't the problem.

If you have changed mouse/keyboard, pc, re-installed the OS, confirmed that no software is to blame and also that no hardware is to blame then what is left..?

Fwiffo · « **Reply #31 on:** Tue, 02 November 2010, 08:52:58 »

Quote from: zefrer;241525

And yes, a 2-5ms _input_ delay on top of a 30ms ping is instantly noticeable to anyone that spends a few hours a week playing FPS games.

I'm extremely skeptical that a delay that small is perceptible on top of other factors. There's a 17 ms delay between screen refreshes for goodness sake. Again, it would be a trivial thing to do a blind test to see if it's possible to tell the difference.

zhuak1 · « **Reply #32 on:** Tue, 02 November 2010, 09:42:51 »

Guys, when i move too fast. the mouse just stop tracking. the sensivity has a delay.. thats my problem. it seems like i have LAG moving mouse to aim :\

CodeChef · « **Reply #33 on:** Tue, 02 November 2010, 09:52:40 »

Quote from: msiegel;241406

audiophile.

Guitar/bass player too!

zefrer · « **Reply #34 on:** Tue, 02 November 2010, 10:02:41 »

Err what? 17ms delay between screen refreshes? Would _love_ to see references of where you got that from

And I was talking specifically about _input_ delay, not a 2ms increase in ping. Input delay is obvious, you would see it at the interface when selecting menu items for example or typing, before going into the game.

Fwiffo · « **Reply #35 on:** Tue, 02 November 2010, 10:19:02 »

LOL, I used *math*.

I'm assuming a refresh rate of 60Hz. So there is 1/60th of a second between updates of your screen. It isn't possible to update any given pixel on your screen faster than that at that refresh rate. 1/60th of a second is 0.016666... seconds or about 17ms.

After any input action, assuming your software, OS, input hardware, USB or PS/2 bus, etc. all collectively have ZERO lag, there's an average of 8ms before there can be any kind of feedback on the screen at all, hence my skepticism.

zhuak1 · « **Reply #36 on:** Tue, 02 November 2010, 10:31:42 »

Guys, i saw some random guy saying that he was having unstabe hz too and the problem was the motherboard usb ports. maybe i have that problem too.

And nice, i've got a reason to RMA the keyboard. the SPACE key is making so ****ing noise it seems that its going to blow up. Maybe im going to buy EC1 & Tarantula. What do you think about this 2 gadgets?

and here's a print with my proof.

zefrer · « **Reply #37 on:** Tue, 02 November 2010, 10:42:41 »

"Lol".. That would be the case if we were talking about CRTs with a 60hz refresh rate..

The 60hz on an LCD is a frame rate cap, what matters is the pixel response time which is some 2-5ms on most TN based LCDs.

zhuak1 · « **Reply #38 on:** Tue, 02 November 2010, 10:49:12 »

focus on my problem

(

zefrer · « **Reply #39 on:** Tue, 02 November 2010, 10:53:24 »

Sorry

As I said earlier the higher Hz can be a result of the PC locking up for a second or whatever which would also explain what you are describing. Since you say you have used another PC with the same problem what makes you think it's your motherboard's usb ports?

zhuak1 · « **Reply #40 on:** Tue, 02 November 2010, 10:58:47 »

unstable mouse hz -» usb port? Since im only having this problem in Asus Boards... the mouse sensivity is really ****d up. i cant explain exactly but it seems that he gain acceleration and some times when you move fast or you do an 360/180 the mouse doesnt track.

Fwiffo · « **Reply #41 on:** Tue, 02 November 2010, 11:06:39 »

Can a mod split this thread?

@zhuak1: Have you tried hooking up with a PS/2 adapter just to see if there is a difference?

@zefrer: Your screen can still update, at most, 60 times per second. The pixel response time is the delay between when the display receives the signal and when the pixel's color has actually changed. If the DVI interface is operating at 60Hz, it's just not possible to get new information to the display more often than 60 times per second.

zefrer · « **Reply #42 on:** Tue, 02 November 2010, 11:10:50 »

Fwiffo that's not the case, LCDs do not work like that. Here.

Zhuak have you tried the same keyboard/mouse on another PC and had the same results or not? FYI Asus has some of the best and most stable motherboards on the market, I would expect you to _not_ have issues with it, not the other way around.

zhuak1 · « **Reply #43 on:** Tue, 02 November 2010, 11:18:53 »

dont have this problems on lan, always stable.

muchadoaboutnothing · « **Reply #44 on:** Tue, 02 November 2010, 11:19:49 »

Quote from: zefrer;241618

Fwiffo that's not the case, LCDs do not work like that. Here.

Even so, Windows is going to allot an LCD 60 images a second. Via AVforums:

Quote from: AVSForum

Response Time
Strict Definition: The time required for a liquid crystal to change orientation.

Refresh Rate
Strict Definition: The time alloted for each frame of video to be displayed on the screen divided into one second. Active matrix displays like LCD use the entire alloted time to display a frame.
LCD blurring is a combination of long response-times and long hold-times. Reducing the response time with overdriving techniques does not help the hold-time. Reducing the hold time by increasing the refresh rate does not change the response time. You have to do both to really reduce blur.

And TweakGuides:

Quote from: TweakGuide

Ok, so if an LCD monitor doesn't refresh itself many times a second, why does an LCD monitor still require a particular refresh rate setting in Windows? We previously discussed the fact that refresh rates are something only a CRT monitor needs because of the way it physically operates. Well it appears that LCD monitors need to emulate a refresh rate in Windows primarily for compatibility purposes with games and hardware. Games, Windows and your graphics card are all still designed around composing individual frames in the frame buffer, and sending these whole frames to your monitor one by one, with the timing for buffer flipping typically based on Vertical Blank Intervals - all things which were originally required for CRT monitors. Therefore LCD panels have to try to operate on the same basis, despite the fact that they don't have the same physical limitations of a CRT.

Let's look at an LCD's theoretical refresh rate, based on its response time rating. Consider the example of an LCD monitor nominally rated at an 8ms response time. Given 8 milliseconds is 8/1000ths of a second, in one full second it can refresh all the pixels on the screen (if necessary) 1000/8 = 125 times, which makes it equivalent to a 125Hz refresh rate. Yet no 8ms LCD monitor allows you to set a refresh rate even remotely close to this in Windows.

Fwiffo · « **Reply #45 on:** Tue, 02 November 2010, 11:24:05 »

You're confused; if you read the article you would see:

Quote from: wikipedia

However, LCDs normally refresh at 60 fps and it is still possible to have screen tearing if graphics are updated too quickly.

No, LCDs don't have an electron gun that's scanning the screen, and I never said they did, but they still only update at 60Hz. It's not like the video card has random access to the pixels on the display, it sends an updated image at 60Hz. Read this article on the DVI interface if you're not convinced.

It's not a matter of being compatible with windows or anything, it's the way the interface between your video card and your display physically works.

zefrer · « **Reply #46 on:** Tue, 02 November 2010, 11:29:41 »

Yeah, I see it Fwiffo, I am confused indeed

I'll read up more on it later

Fwiffo · « **Reply #47 on:** Tue, 02 November 2010, 11:33:08 »

OK, back on topic. :-)

Quote from: zhuak1;241621

dont have this problems on lan, always stable.

Can you elaborate? Are you saying you only experience lag when playing over the Internet but everything is fine when you're playing over a LAN?

If so, then it's not the keyboard, mouse or USB bus that's at fault.

zhuak1 · « **Reply #48 on:** Tue, 02 November 2010, 11:43:30 »

when i play at lan, the mouse sens seems to be ok. doesn't give me bad tracking or like "extra accel" and YES, i've tried ACCELFIX,CPL MOUSEFIX!

Its like a bug on my board, a bug on mouse hz, a bug on windows.. a bug in mouse. i dont know ill give an example

I move the mouse from here to here

X ------------------ X. Normal, with precision

then i move again

X ------------------ X. Normal..

Then i move again like the same as i was used to do and then..

X ----------------------------------------X like this. This really sucks when im playing..

zefrer · « **Reply #49 on:** Tue, 02 November 2010, 11:55:42 »

Again, have you tried this mouse/keyboard on another PC and had the same issue or not?

Do this. Disable your network connection and try your game again (not an online only game obviously). Do you have the same problem?

zhuak1 · « **Reply #50 on:** Tue, 02 November 2010, 12:08:58 »

yes i've tried. on my moms pc(old old one) i have 499 500 499 500 499 500 499 499 499 500 hz. no 1000hzs. and yes i tried that. :\\.... **** this computer. voodoo me?!? haha..

zefrer · « **Reply #51 on:** Tue, 02 November 2010, 12:18:46 »

And you've reinstalled a _clean_ new OS? In a new location? Without reinstalling over the old one? Without installing _anything_ afterwards except drivers?

zhuak1 · « **Reply #52 on:** Tue, 02 November 2010, 12:23:22 »

maybe its just mobo... :/ never tried that. i install drivers+cs+overclock to 500hz and have this problem

zefrer · « **Reply #53 on:** Tue, 02 November 2010, 12:50:19 »

>.> Try it.

Rajagra · « **Reply #54 on:** Tue, 02 November 2010, 14:00:39 »

Tell me you aren't using a USB broadband adapter.

zhuak1 · « **Reply #55 on:** Tue, 02 November 2010, 15:23:51 »

no just my soundcard, mouse, keyboard. and my router via ether.

rajagra, whats the best mouse avaiable?

im thinking on buying legends edition.

Ive tried kinzu and xai, PERFECT shape.. but accel and prediction? no thanks. 1.1 too slow for me, it has 400 dpi and negative accel.

3.0 has 450?

zefrer · « **Reply #56 on:** Tue, 02 November 2010, 15:37:54 »

Dude, it's not the mouse. But do whatever you want.

zhuak1 · « **Reply #57 on:** Tue, 02 November 2010, 15:45:24 »

yes but 1.1 doesnt fit me..

zhuak1 · « **Reply #58 on:** Tue, 02 November 2010, 16:02:16 »

another pic of the problem

tonyklo · « **Reply #59 on:** Tue, 02 November 2010, 17:36:38 »

if you wana buy a mouse, u must get Zowie EC-1 or 2 ! the sensor is amazing

i hated the xai/ kinzu /

Rajagra · « **Reply #60 on:** Tue, 02 November 2010, 18:59:33 »

Quote from: zhuak1;241756

another pic of the problem

I was unable to replicate anything like that until a few seconds ago, on my older, slower machine.

Problem was here:

This was the only time I've seen the frequency go much over 125 on that PC. Also the only time I've seen acceleration appear to happen.

It happened at the instant my wallpaper changer app kicked in. This would have loaded a 1920x1200 jpg file from the disk. So possibly disk I/O related.

...confirmed ... if I run a disk defrag I see unusual mouse scan frequencies often.

Maybe your disk setup has room for improvement. Or you have too little memory and the pagefile is busy. Do you have at least 2GB?

zefrer · « **Reply #61 on:** Wed, 03 November 2010, 07:40:07 »

As was mentioned earlier, it is most probably a software issue, further enhanced by the fact that Raj has replicated the consequences. That's why a new clean OS install was suggested.

zhuak1 · « **Reply #62 on:** Wed, 03 November 2010, 09:12:02 »

i've 2Gb kingston hyperX

so?

zhuak1 · « **Reply #63 on:** Wed, 03 November 2010, 12:58:23 »

Guys do you have counter strike 1.6 installed to watch a small demo about my sens problem?

zefrer · « **Reply #64 on:** Wed, 03 November 2010, 13:02:33 »

For the umpteenth time, do a clean OS install. Sorry but the problem is definitely not going to fix itself if you keep ignoring suggestions on what to do and instead do nothing.

CodeChef · « **Reply #65 on:** Wed, 03 November 2010, 15:38:09 »

Quote from: zefrer;242175

For the umpteenth time, do a clean OS install. Sorry but the problem is definitely not going to fix itself if you keep ignoring suggestions on what to do and instead do nothing.

This. Stop ignoring them. They're actually trying to help.

002 · « **Reply #66 on:** Wed, 03 November 2010, 16:23:32 »

Quote from: Fwiffo;241160

A keyboard hooked up through PS/2 will have more air and presence with fuller bass and more dynamic mids.

Remember, you have to allow it to burn in over a few days. Running games non-stop overnight should do the trick.

keyb_gr · « **Reply #67 on:** Thu, 04 November 2010, 09:06:37 »

With polling based data transmission as used by USB, loss of individual packets definitely is not out of the question. On my historic machine here, a USB keyboard will occasionally drop a few characters under high load, in spite of a dual processor setup.

Troubleshooting of such issues should be similar to that of sound problems. Maybe the DPC latency checker will already show something.

CodeChef · « **Reply #68 on:** Thu, 04 November 2010, 10:25:37 »

Quote from: 002;242242

Remember, you have to allow it to burn in over a few days. Running games non-stop overnight should do the trick.

Don't forget oxygen-free wires in your cables. They should be make out of pure gold.

woody · « **Reply #69 on:** Mon, 08 November 2010, 11:03:16 »

Quote from: ripster;242488

I can see an argument for a character sometimes not being scanned by the local microcontroller but a USB packet being "lost"?

Yes, USB packets might get lost. Isochronous transfers (like streaming audio/video) don't get retries, all others do.

Rajagra · « **Reply #70 on:** Mon, 08 November 2010, 11:32:11 »

Sometimes (not often, but enough to notice) my PCs miss the fact that I've released keys, mainly when gaming. Same with mouse buttons. Always over USB so far, but that could be because I use USB more.

It doesn't say much for the polling algorithm if you think about it. I thought the main feature of standard USB polling is that it specifically asks (125 times per second or more!) which keys are down. Even if packets are lost shouldn't it self-correct almost immediately? Could be a Windows issue, and because I have multiple input devices, but the simple fact is, it gets confused.

woody · « **Reply #71 on:** Mon, 08 November 2010, 13:16:59 »

USB packets may get "lost" in the sense, that the recipient might see garbled data. That is actually easy to achieve. If it is isochronous data - it is lost, no retries. Any other transfer type - it is retried until acknowledge.
What is held in the transmitting endpoint buffer is most likely not changing during the retry period. And of course, when USB host hardware receives some data, the time it takes to finally reach the application (and in this context, the HID, in between) depends on OS load, driver quality, etc.

woody · « **Reply #72 on:** Mon, 08 November 2010, 14:43:09 »

Quote from: ripster;244349

Keyboards run under USB "Interrupt Transfer" mode so a lost keyboard character should be theoretically unlikely.

We're on the same page. Packet may get garbled at the first (expected) time, but will eventually get there after some time with retries. Maybe I explain in a lousy way. Beware the meaning I imply in "lost", too.

Quote

Wouldn't suprise me if apps or the OS loses it though.

Exactly my point.

EDIT: Reading it over, I can see that in my posts I didn't clarify that HID data goes via interrupt transfers. I included isochronous for the sake of showing that USB cannot be described simply in few words.

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Author Topic: [6gv2] (Read 17669 times)

woody

woody

woody