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View Full Version : Vsync + SLI AFR is a no go


Guz
01-11-06, 08:56 PM
SLI AFR performance with vsync on is definetly not on par with performance with vsync off. To prove my point, in a game such as COD2 in the exact same spot i get over 80fps with vsync off, but with vsync on it never goes above 40fps. If performance were the same i would be getting at least 60fps which is equal to the refresh rate of my lcd.

Any one else notice this?

emailthatguy
01-12-06, 12:15 AM
and you shouldnt. if you got fps above 60 w/ vsync on then the vsync function of the driver would be broken.

if your vsync is 60 fps for your lcd then you should be 60fps "most" of the time provided your card can handle what its rendering pretty easilly. this is why people use dxtweaker to enable triple buffering in directx for example. the triple buffer allows for smoother rendering and thus making it easier for the card to to feed the display at a given rate. (very very loose laymans terms here for the sake of discussion).

from what i understand if your card needs to use more rendering cycles and has to drop below the syncrate i believe its fallback is half the syncrate or 30 fps in your case if i remember how it works correctly.

the most common reason to use vsync is to eliminate "tearing" seen in high fps situations.

hope this helps

Peoples-Agent
01-12-06, 07:13 AM
Don't worry man, some games you can use DXTweaker to force Triple buffering.
Which gives you more fps with VSync on.

emailthatguy
01-12-06, 07:59 AM
but to clarify, on your setup, with triple buffering youll never see more than 60. the idea again, is to keep 60 fps rock stable provided your hardware can handle pumping out that game youre trying to play w/ no dips whatsoever.

Guz
01-12-06, 12:44 PM
Guys i don't want to sound arrogant or anything, but i started the sticky thread in this forum about dxtweaker, but that's not my point.

What i was trying to point out, is that with VSYNC-OFF i get 80fps and at the same spot with VSYNC-ON i get 40fps. If my LCD refresh rate is 60, then i should be getting 60fps and NOT 40fps. Thus, AFR performance is not the same in both of these situations.

I hope this clears things up, and i can understand the confusion since english is not my native language.