V-synch

woodchip · Post by **woodchip** » Thu Mar 11, 2004 8:43 am

Can someone explain what v-synch does. I know we are supposed to have it turned off for d3 timetests to max out fps. I just never thought much beyond that. Should it be turned on for the more modern games?

CDN_Merlin · Post by **CDN_Merlin** » Thu Mar 11, 2004 9:08 am

It synchs your FPS with your monitors refresh rate.

DCrazy · Post by **DCrazy** » Thu Mar 11, 2004 12:42 pm

Theoretically that's all it should do, but poorly-coded games tie certain things to the framerate (such as the famous High-Framerate Omega Bug), so instead of just No Screen Tearing (part of the screen shows one frame while part of the screen shows another, due to the frame being updated while the monitor is still refreshing) vs. Framerate (smoothest gameplay possible), more factors can enter the equation thus making the decision to disable VSync more complicated.

Since nobody uses Omega anyway, everyone turns VSync off in D3.

bash · Post by **bash** » Thu Mar 11, 2004 1:06 pm

Chipper, if your other games cannot sustain a FPS equal to or exceeding your refresh rate (i.e. you get 35 fps but your monitor is set to 85 Hz) then it's been my experience that gameplay is smoother v-sync'd. If your FPS exceeds your refresh, turn v-sync off.

Pugwash · Post by **Pugwash** » Thu Mar 11, 2004 2:23 pm

I play with v-sync on, 85mhz at 1200x1600. everything looks awesome and game play is as smooth as can be. I cant stand the tearing its soooo fugly.

Mobius · Post by **Mobius** » Thu Mar 11, 2004 4:29 pm

Tearing is really only an issue with V-Sync off when the FPS rate is low. Once FPS exceed the refresh rate there is no visible tearing and no point in V-Syncing.

V-Sync can however, solve some issues in some games. On my old Matrox card, enabling V-Sync prevented small screen lock-ups.

Whatever works for you.

My page at http://planetdescent.com/d3help/framerate.shtml has a bit of info on this subject.

woodchip · Post by **woodchip** » Thu Mar 11, 2004 4:49 pm

Thanks for the input. I guess I have to go into the games and see how fast the fps's are.

Suncho · Post by **Suncho** » Thu Mar 11, 2004 5:07 pm

Mobius wrote:Tearing is really only an issue with V-Sync off when the FPS rate is low. Once FPS exceed the refresh rate there is no visible tearing and no point in V-Syncing.

WRONG The higher your framerate, the more tears there are on the screen. If your framerate is exactly double the refresh rate, you will see one tear line on the screen at all times. If it's 6 times the refresh rate, you will see five tear lines on the screen at one time (because it's drawing parts of 6 different frames with the tear lines separating them.)

Teddy · Post by **Teddy** » Thu Mar 11, 2004 9:10 pm

I play with vsync on at all times, this is one of the reasons i hate my ati card. they are always breaking some part of it...

Anyway, v-sync is very nice to turn on as long as your framerate stays ABOVE your refresh rate. My min framerate when i run a timetest is 135fps, so i play at 1024x768 at 100hz. this keeps my game running at a constant 100fps, gameplay is smooth and each frame is clear. If your cpu is too slow to keep up with your refresh(even if it's as low as 60 or 75hz) then turning v-sync on will still give you pretty frames but it will run at half what the refresh is since it cant keep up(when your cpu cant put out the 60 or 75 fps). this will mess up your play control as it will jump around when the framerate does. so make sure you dont use vsync with too high of a refresh for your cpu.
I dont know why so many people run at 400 fps and let the graphics tear so bad. many say they dont notice it but my experience is just that many dont take the time to set it up right.

And yes, i can use omega.....

AceCombat · Post by **AceCombat** » Thu Mar 11, 2004 10:26 pm

i run VSync @ 120 Hz on my trinitron and it works flawlessly

Avder · Post by **Avder** » Fri Mar 12, 2004 4:35 pm

Mobius wrote:Tearing is really only an issue with V-Sync off when the FPS rate is low. Once FPS exceed the refresh rate there is no visible tearing and no point in V-Syncing.

Wrong wrong WRONG!!!!!!

If you start to exceed your monitors refresh rate in FPS (say, 140 FPS @ 85Hz Refresh) You WILL start to get some tearing. Its that simple. In order to minimise this tearing, you'll want to set your monitors refresh as high as it can go without damaging it. You will see some difference. I saw a lot of difference switching from 60hz @ 800x600 to 85Hz @ 800x600 in the game Need For Speed 3 (A DirectX game). Much less tearing at higher refresh rates. There will always be some tearing, but not much. Once again Mobius, you have opened your mouth without doing the prerequisite research.