Know your vsync

[von Pilsner]

Originally Posted by louisv

In order for Vsync to keep everything synchronized, when it doesn't get 60 fps from the computer, it falls off to 30 fps because otherwise there would be tearing. Think about it, you can't have say 45 fps on a 60 fps monitor, there would be partial frames along the way...60/30=2 and 60/45=4/3=1.33

If the computer cannot get 30 fps, say it gets 29, then vsync will make it fall to 15 fps because 60/15=4, a whole number for whole frames.

So use it knowingly.

Louisv

Hmmm, all the games I play either cap out at 60 or 30 fps using vsync (depending on the game). I have never experienced or heard of this proportional vsync frame rate issue you are talking about.

In my experience vsync does not do what you say it does, the tearing is from more frames being sent to the monitor that it can display (>60Hz/fps for me) and not from an odd number of frames (if I am at 60fps or less my monitor can always keep up so there is no tearing).

I believe vsync can contribute to input lag depending on the game and computer.

[Codex]

VSync doesn't work that way. Vsync (either set in game or the graphics card driver) ensures that before the next frame is drawn on your display, your monitor has completed the current draw call. Only then will the next draw call be made.

You can still have odd numbered frame rates or lower frame rates than what you've set your refresh rate on your monitor (i.e. most LCDs max at 60 Hz). It just means your PC isn't processing the game engine fast enough to get the max frame out.

Say for example the game engine is pumping out frames at 43 fps and your monitor's refresh is set to 60 Hz, with Vsync on you wont (or shouldn't) see tearing as the game or graphics card driver wont display a frame until the current draw call on the monitor is done. What you may see however is a slide show if the frame rate drops below 30fps