hi everyone, i currently have 2 SLI GTX580 and i would like to know what is better running Vsync on or off? cause for example running Dirt2 or BC2 i get massive FPS from the looks of it turning Vsync ON the games seen to run SUPER SMOOTHER i already know i can get massive fps on those game but running them at 60FPS seen to run better for my monitor, like i said everything seen smoooooother and perfect.

Some prefer it off, some on. Try it both ways and see what you like :) I prefer VSync off usually because sometimes it can seem to add a bit of mouselag.
 
Also keep in mind that if your FPS cannot reach 60FPS for whatever reason, it will be cut in half to 30FPS. (unless you have triple buffer on)

i have fraps and i see 60fps all the time even in scenes that are extreme, am always getting 60fps steady.

EVGA_JacobF

Some prefer it off, some on. Try it both ways and see what you like :) I prefer VSync off usually because sometimes it can seem to add a bit of mouselag.

Also keep in mind that if your FPS cannot reach 60FPS for whatever reason, it will be cut in half to 30FPS. (unless you have triple buffer on)

thats not quite correct, the affects of an unstable framerate with vsync differ in many games, especially where the engine manages its frame queue.
 
further, the drop for those games which do not, is not an immediate cut by half but a divisor of 60. so it can either be 45, 30 or 20 fps, oblivion for instance will drop to 45 first, then 30, then 20, then 15 if it can't maintain a framerate at or around the step above it.
 
Further, Vsycning a massive framerate can cause more lag than vsynching a lower framerate, this is the case in games built on MT Framework, like DMC4.
 

If your framerate is above refresh rate (except for the multiGPU case) you should definitely not use anything more than 0 frames of render ahead. Triple buffering as I described in my previous article (and as NVIDIA does in OpenGL) will be a good option, but double buffered w/ vsync or no vsync will definitely be better than any sort of render ahead.

If your performance is below refresh rate, you'll want to either use no vsync, exactly 1 frame render ahead, or triple buffering. double buffered vsync (0 flip queue/pre-rendered frames with vsync) will give you a significant drop in performance and increase in input lag when performance is below refresh. This is as you say -- by as much as 50%. But only when performance is already below refresh.

 
The triplebuffering provided by D3DOVeride is not the same as nvidia does in opengl, the opengl method does not add an extra frame to the flip queue (the flip queue is a chain of frames prepared prior to being sent to the video card, and is in addition to the cpu prerender in the driver itself). This additional frame in the flip queue increases input latency.
 
DirectX typically sets 2 frame flipqueue (d3doverride makes it 3), + the drivers 3 frame prerender + the backbuffer.
 
at default settings this is 5 frames in the software queues before the card starts rendering. this is why setting the driver to 0 is best if you plan to force triplebuffering on the game.
 
 

The original Crysis exhibits horrible mouse lag with vsync on

 
im looking into this atm ;)

i use a 30fps cap, the game doesn't need any more then that and it allows using visual settings that would otherwise cause 30fps with mouse lag.

if u don't really see performance above 60 FPS then it's totally pointless as it will reduce the FPS u get further and the only reason to use it is for screen tearing anyway.

 
Unfinished frames can be flipped in to the front buffer at any point when vsync is off. regardless of whether your FPS is higher or lower than the refresh rate.
 
If your FPS is heavily exceeding the refresh rate, then there is a high possibility of incurring a lag penalty (on 59.94 displays capping to 58fps + vsync usually resolves the lag.)

MasterGohan

Already hinted at by Squall's explanation, the big thing to remember is that a poorly coded game can have game-logic (including network logic) tied in with rendering logic (same thread).

In otherwords ... if you're getting 240fps with vsync off, the game engine may be performing 240 client ticks per second.  Flipping vsync on with a 60hz display may mean adding almost 12ms between client-ticks (that's nothing to scoff at).  That ain't something that is imperceptible and can have a radical impact on a gamer.

People aren't crazy that say that vsync off yields less lag in games online, sometimes it really does.

games that handles cursor positioning via the tic rate are a problem, particular older FPS's.  i only recently learny that homeworld 2 defaults to a software cursor, and adding -hardwarecursor as a command switch cleared up all the lag.

Same problem i've had with eduke32, the build port runs at 1000fps uncapped and when vsynced the input lags quite heavily, whilst on a far slower machine its not nearly as bad.
 
as you said, limiting the fps to around 60 (58 in my case) resolved the lag.
 
I expect the MT framework used in DMC4 may have had the input being tied to tic rate, as even a gamepad experienced a slight delay. It was barely even noticeable, but im able to detect the difference between click and response as well as the slightest of movements from a gamepad. It almost was like the input was being buffered when vsync was enabled. so i ended up settling for the 120fps frame limit.  I never bothered to check if i could enable a custom fps cap to use along side vsync, as at 120fps the game had almost no tearing anyway.
 
Just cause 2 is an example of a recent game thats tieing input to tic rate, along with game timing itself from what i could tell given the game had instances of slowmo and turbo going from 30 - 60 fps when adjusting the camera.

the Cutting in half is incorrect..period. Interlace and Non interlace (CRT TECH) would be a cut in half... 
 
I have always used Vsync... With all the Vsync talk here, saving performance helping input lag, I tried the other day to play without.... 10 minutes into stalker with Atmosfear 2 installed , A huge lightning storm started...everytime Lightning happened HUGE tears across screen....  and mouse input was same...except everytime I turned fast from a noise in the dark...my screen TEARED!!!! YEAAAAAA..NO!  Turned it back on and resumed playing and was sucked into the amazing atmosphere that Stalker with the right mods is, minus the SCREEN TEARS to vividly remind me of technology running the experience.

I use VSYNC on BC2, my monitors RR is 60hz, so with VSYNC it's just pure butter, no mouse lag! TB ON!
No point of having 150fps, when your monitors RR is only 60-85hz! If you can cap your fps w/o VSYNC, even better!

what he said. lol .i've never used it and didn't notice any tearing ever with or without..maybe i will try it to see.i get 125 fps in BO now,so i haven't really considered it..

EVGA_JacobF

Some prefer it off, some on. Try it both ways and see what you like :) I prefer VSync off usually because sometimes it can seem to add a bit of mouselag.

Also keep in mind that if your FPS cannot reach 60FPS for whatever reason, it will be cut in half to 30FPS. (unless you have triple buffer on)

I leave vsync off globally for everything in the Nvidia Control Panel and the screen tearing doesn't bother me.