Vsync ON == Mouse Lag!

[flexy]

Problem:

I have a 8800 GTS 512MB on a 60hz Widescreen LCD.

I am using 174.70 drivers.

*Every time* when i enable Vsync in games i get a very noticeable "mouse lag"...i dont get nay mouse-lag whatsoever if i run without vsync on.

There are some games (WoW) where i prefer Vsync..but the lag is a bit annyoing.

Btw. this applies to any games, even games which can run with 200+ FPS, like HL2 engine on the GTS...Vsync On: Mouselag..

Why?

 

[kylebisme]

By default vsync uses double buffering, which means the GPU has to sit idle after it finishes drawing each new frame to the back buffer while waiting for the refresh to be completed from the front buffer, hence the lag you notice. Triple buffering reduces that latency by allocating memory to store a frame while waiting for vsync, so the GPU can continue rendering as it does when not using vsync and potentially produce a newer frame in time for the next vsync. You can use D3DOverrider which is included with RivaTuner to force triple buffering D3D applications.

 

[flexy]

TSM,

thanks. Yes i know about all the technical details. I forgot to say that i never had a mouse-lag issue gaming on my old CRT, or at least not that i remember. Yes i have Vsync and Triplebuffering on...but the lag is still there when i play using Vsync.

I wonder if its related to the lower refresh of the LCD.

 

[GundamSonicZeroX]

Originally posted by: flexy
I wonder if its related to the lower refresh of the LCD.

I would imagine so. I hate the lag I got on my old 60hz LCD when I enabled V-Sync.

 

[ArchAngel777]

I have never noticed input lag at all... I tried to find it on the dad's plasma TV, which is supposed to have it, but NEVER once noticed it. I spent 10 minutes to try and get this 'lag' to show.

I also enabled Vsync + TB and notice no lag on my LCD. I move the mouse and it instantly moves. I have tried to move it quick to spot this lag, but am unable too.

It must be something that only some people notice. It could be that their eyes are sharper, quicker, etc... But, in some ways, I would consider myself lucky that I do not notice it, because look how miserable people are. They either live with tearing (something I noticed and abhore, both CRT and LCD) or they live with their input lag (something I never notice). So, I guess life is good for me as a result of perhaps my own visual human limitations. *shrug* no complaints here.

But one thing I don't understand is how a CRT user can stand imperfect geometry. I'd rather have slightly less accurate colors and contrast than a line that isn't perfectly straight. Even the best CRT's have geometry issues.

 

[Munky]

I also noticed input lag with vsync, even in my own 3-D applications, not sure if it's because I switched to a 27" LCD or a Nvidia video card (or both).

As far as colors vs. geometry, it depends on what you use the monitor for. For games and movies I'd chose colors over geometry any day... but there's something to be said about gaming and movies on a 27" screen, even with imperfect colors.

 

[whiplash willy]

Forget about VSYNC and turn up the refresh rate on your LCD, turn it up as high as you can. After increasing the refresh rate on my LCD from 60 to 75hz, I no longer needed to use VSYNC to get rid of tearing.

Here is a good read on VSYNC:

Vsync

 

[taltamir]

wouldn't triple buffering the mouse lag more? I would imagine you would want to use D3D overrider to completely eliminate buffering.

There is always the chance that it isn't their eyes or brain, but simply a case of a driver bug affecting their specific system. some people get their pcie 16x set to 1x for some reason, some get their videocard downclocking automatically due to thinking it has too little power (on beefy PSUs), there are a plethorea of system specific errors. When the brand of PSU you have can cause driver bugs, well, then so can anything else.

 

[BFG10K]

I wonder if its related to the lower refresh of the LCD.

Not the refresh rate per-se, just the general image lag LCDs have.

After increasing the refresh rate on my LCD from 60 to 75hz, I no longer needed to use VSYNC to get rid of tearing.

LCDs that can truly go above 60 Hz are rare. The rest of them will do something like skip every fifth refresh when you use 75 Hz.

wouldn't triple buffering the mouse lag more?

In theory triple buffering should improve the situation but in practice I?ve found it can make things worse.

I would imagine you would want to use D3D overrider to completely eliminate buffering.

If you eliminate buffering you couldn?t render anything. Two buffers are needed at a minimum to ensure there?s no flicker during animation.

 

[taltamir]

wouldn't triple buffering the mouse lag more?

In theory triple buffering should improve the situation but in practice I?ve found it can make things worse.

I would imagine you would want to use D3D overrider to completely eliminate buffering.

If you eliminate buffering you couldn?t render anything. Two buffers are needed at a minimum to ensure there?s no flicker during animation.

[/quote]
Sorry I meant make into single buffer. I mean, what kind of theory is that where triple buffer will have less input lag? Triple buffer is reducing stutter and image lag at the cost of increased input lag.

Time = start
Single buffer:
Frame 1 is displayed.
Frame 2 is rendering.
Frame 3 will not render until frame 2 is displayed. (or it will and discard, depending on vsync)

Double buffer:
Frame 1 is displayed.
Frame 2 is rendering.
Frame 3 will render ASAP.
Frame 4 will not begin rendering until frame 2 is displayed. (or it will and discard, depending on vsync)

Triple buffer:
Frame 1 is displayed.
Frame 2 is rendering.
Frame 3 will render ASAP
Frame 4 will render ASAP.
Frame 5 will not begin rendering until frame 2 is displayed. (or it will and discard, depending on vsync)

without vsync each frame is rendered ASAP, so the faster the video card, the less time passess between frames. With vsync, each frame is matched to be 1/60th of a second apart.

Time meaningfully progresses every 1/60th of a second, when a new frame is sent to the monitor. If your video card is fast enough to render 240fps for game X, then it will render and DISCARD about 3 or so frames before the next monitor refresh. Meaning that regardless of buffer the next frame WILL display your input. If your video card is vsynced that it would have instead rendered 3 "future" frames that are each 1/60th of a second apart and EACH is going to be displayed, resulting in X/60th of a second input lag.

vsync off (250fps, frames 1/250th of a second apart):
time=0 : Frame 1 is displayed.
time=1/250s: Frame 2 created.
time=1.5/250s: input from user
time=2/250s: Frame 3 created.
time=3/250s: Frame 4 created.
time=1/60s: Frame 4 begins sending to monitor
time=4/250s: Frame 5 enters buffer while frame 4 is being sent. Resulting in tearing as the top half of frame 4 and bottom half of frame 5 are displayed.

vsync on (250fps CAPABLE card working at 60fps) :
time=0 : Frame 1 is displayed.
time=1/250s: Frame 2 created
time=1.5/250s: input from user
time=2/250s: Frame 3 created.
time=3/250s: Frame 4 created.
time=1/60s: Frame 2 (which is missing the last input) begins sending to monitor, when it finishes, frame 5 will begin rendering.

Basically with very high FPS situation, input lag will be introduced by triple and double buffering. (2/60th and 1/60th of a second respectively). But the tearing is eliminated. With low FPS the input lag is lessened because it is less like that frames are rendered ahead (since the video card is just not fast enough), but it might still occur in times of high FPS spikes. However tearing is completely gone.

If you think vsync reduces input lag then you are just confusing input lag with lag in general. Or your CPU is choking, and reducing the framerate by capping it allows quicker calculations.


PS. Input lag could mean one of two types. Where you gave input but it did not display on the next image (it took X miliseconds before the gun animation started). Or when you gave a command and it did not REGISTER with the computer until some time later (i clicked first but died).
Oh wow, I just understood the stutter in quad GPU AFR rendering.. it all makes perfect sense now...

Anyways, if you are suffering from cases where you shot first and still died that this is a case where you want to unburden your CPU as much as possible, in which case vsync + triple buffer means you are doing the LEAST amount of work per image displayed, resulting in a snappier system, that will more quickly detect your click.

When I was saying "image lag" before I meant stutter between pictures caused by low FPS. Example: crysis at 5fps lags and looks like a slideshow.

 

[Phynaz]

You're off by one.

What you call single buffer is actually double buffer, and what you call double buffer is actually triple buffer.

 

[taltamir]

ah... right... cause the currently displayed image is ALSO a buffer... oops. Thanks..

I think I got it... What you are probably experiencing is STUTTER, not input lag.

Input lag : I pulled the trigger first and yet he killed me.
Stutter : I pulled the trigger, and then it suddenly jumped to 50% done with the firing animation.

Buffering + Vsync = reduced input lag and no tearing, but increased stutter.
No vsync + high FPS = no stutter at all, but increased input lag and tearing.

Just reduce your buffering to double. if it STILL bothers you, then you have to choose which bothers you more.

 

[flexy]

guys, i am not talking about the LCD mouselag!! The LCD itself doesnt lag, i can see since it is 5ms/2ms (gray to gray), pretty fast and i can run whatever i want without vsync fine. its NOT the monitor.

It must be an issue with the drivers, or just general an issue which appears *only* using vsync and LCDs. If i have time i can test tomorrow on my other PC on the CRT....but the test would be flawed since it COULD also be a Nvidia issue, the other PC has an ATI card.

Btw. the lag does NOT get better with "maximum pre-rendered frames" to 2..i also can test whether this happens in OpenGL, eg running WoW in OpenGL. I notice this lag in all games (mostly RPGs) where i dont care about speed/tearing and turn on Vsync.

 

[LegitimateBusinessman]

I have this same problem, and if you have a squiz on the internet at large it seems common - vsync on = input lag. I am not joking when I say that if I forced myself to play with vsync enabled for an extended period I would eventually vomit from a combination of anger and nausea.
My framerate is anywhere from 70 to 110 in most games, and with vsync on in COD it never flutters below a solid 60fps. Without vsync there's no mouse lag whatsoever and if it hovers around 90fps everything is fine and dandy. However, it doesn't do that all or even most of the time - 75 is about average, and the absolute worst possible framerate for suicidal tearing on a 60hz monitor. God I hate computers sometimes.

 

[zod96]

I use vsync on my LG L227 and I notice no mouse lag at all. My mouse movments are instant. There is no way I could play without vsync in games now. Its sooo much smoother with it on

 

[Grinja]

I found that Quake 4 had crazy lag when I used vsync ... no other game currently comes to mind though.

 

[Emperor88]

Originally posted by: LegitimateBusinessman
I have this same problem, and if you have a squiz on the internet at large it seems common - vsync on = input lag. I am not joking when I say that if I forced myself to play with vsync enabled for an extended period I would eventually vomit from a combination of anger and nausea.
My framerate is anywhere from 70 to 110 in most games, and with vsync on in COD it never flutters below a solid 60fps. Without vsync there's no mouse lag whatsoever and if it hovers around 90fps everything is fine and dandy. However, it doesn't do that all or even most of the time - 75 is about average, and the absolute worst possible framerate for suicidal tearing on a 60hz monitor. God I hate computers sometimes.

What system/gfx card config/screen are you using?

 

[taltamir]

how is this thread still going on? look at the dates...

 

[LegitimateBusinessman]

Originally posted by: Emperor88

What system/gfx card config/screen are you using?

Phenom 9850BE @ 3ghz
4gb OCZ ReaperX
3870 + 3870X2
24" LCD
Razer Lachesis pit viper of a mouse with polling rate set to 1000Hz

 

[ed35]

I would just like to say to everyone looking to use VSYNC and NOT experience mouse/input lag.... Simply limit your FPS to 59. I don't know why this works, but it does for me with every single game (TF2, Far Cry, WoW, CSS) and I experience zero tearing, the smoothest gameplay (SLI seems to perform better in most games with vsync on), and no input lag.

 

[dguy6789]

Not all games have a method of limiting the fps without using vsync.

 

[brblx]

i think you guys have other issues. i use vsync, triple buffering on a 21" lcd and have never had any input lag with the exception of maybe one of two obviously consolitis-ridden games.

and i grew up playing quakeworld on a crt, i think i'd notice.

 

[dguy6789]

Originally posted by: brblx
i think you guys have other issues. i use vsync, triple buffering on a 21" lcd and have never had any input lag with the exception of maybe one of two obviously consolitis-ridden games.

and i grew up playing quakeworld on a crt, i think i'd notice.

It's definitely vsync. The input lag isn't large, but it's noticeable. It doesn't bother everyone, but it does bother some. It's happened to me on every computer I've ever owned with Nvidia or ATI and on every monitor I have ever had both CRT and LCD. If you've used vsync for years, you probably are long since used to it. If you haven't used vsync for years, it's very noticeable when you turn it on.

 

[brblx]

are you saying this is present on CRT's as well? i had never heard of 'mouse lag' until lcd's (and wireless mice) came out.

i never vsynced on a crt, because tearing never seemed to be a problem with quake or similar games of the era. i think half-life was the first game where i noticed it (still on a crt), and it didn't bother me until i moved to an lcd.

 

[dguy6789]

Yeah it happens on CRTs as well. The screen doesn't have anything to do with it really. Enabling vsync makes a game's view move around in a laggy fashion compared to your mouse's movements. Disabling vsync makes it much more responsive and snappy.