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View Full Version : Vsync: On = FPS going from 90+ to 28?


telackey
11-13-03, 11:54 PM
If I turn Vsync on in JK2 or the Jedi Academy demo (only things I have tested much yet) my framerates plummet. In JK2 at 1600x1200 they go from averaging nearly ~100 (if maxfps isn't set) to ~28-30.

I would obviously prefer Vsync On, but that makes it less enjoyable overall.
I do think I see a little tearing at times...

I have BFG 5900 and a P4 2.4GHz, and 'twinview' Cornerstoner p1600 monitors.

I have tried replacing my monitor "drivers" without any difference.

Also, does imposing a refresh rate override in the driver imply Vsync anyway?

stncttr908
11-14-03, 12:08 AM
Correct me if I'm wrong, but if your fps dips under your refresh rate, vsync will halve your fps in order to compensate? This is why I don't use it, because with eye candy such as max AF and AA turned on, I can rarely manage a constant 85 fps on 16x12 in any game.

tEd
11-14-03, 12:49 AM
if you have vsync on as already said by stnc.... you framrate will be 1/2,3,4... of your refreshrate if your fps drops below it


example by a refreshrate of 100:

if the fps drops below 100 your fps goes down to 50 , if it drops below 50 it goes down to 33 and so on....

there are 2 ways to avoiding this:
1. set vsync off
2. use triple buffer while having vsync on

Greg
11-14-03, 03:40 AM
Yeah, bummer OpenGL doesn't support tripple buffering. Vsync will give you a 'fraction' of your refresh such as 1/2 or 1/3 etc. Due to varying frame rates and stats rounding (accumulated results over a second or such) you will often not get exact expected values.

CaptNKILL
11-14-03, 02:23 PM
*cough*see my sig*cough*

Nutty
11-14-03, 04:49 PM
Yeah, bummer OpenGL doesn't support tripple buffering. Vsync will give you a 'fraction' of your refresh such as 1/2 or 1/3 etc. Due to varying frame rates and stats rounding (accumulated results over a second or such) you will often not get exact expected values.

Most drivers enable triple buffering automatically if theres plenty VRAM spare. I get triple buffering in all my games fine. CS, COD, Q3 and theyt're all running in OpenGL. You probably need to use rivatuner to turn it on or something.

Greg
11-14-03, 07:22 PM
Originally posted by Nutty
Most drivers enable triple buffering automatically if theres plenty VRAM spare. I get triple buffering in all my games fine. CS, COD, Q3 and theyt're all running in OpenGL. You probably need to use rivatuner to turn it on or something.

Cool, I'll have to have a new look. Last time I experimented was with Quake3 on my Geforce3 and could never get tripple buffer goodness.

Side note: I notice not all DirectX games enable this or have the option which is unfortunate. Maybe they figure someones going to run 1600x1200x32x4aa and use up all their vram.