Triple Buffering in Snow Leopard

[unwinded]

Anybody know if it's possible to force triple buffering within OSX for OpenGL games? In Windows there is usually the option of turning this on in the video card's control panel for OpenGL games (Direct X requires a 3rd party override utility to do so, but OSX doesn't use Direct X anyways).

Turning on vsync in Portal for example (mac version) halves the framerate whenever it drops below my monitor's 60hz refresh. This is generally the reason why people disable vsync but then you get torn frames every time the game isn't running at 60fps (for a 60hz display) even when it exceeds 60fps. Triple buffering + vsync is the magic combo the eliminates screen tearing in windows and all modern graphics cards have the vram to support it. The only downside is it is known to cause mouse lag (but so does running vsync itself) in some games for some people.

Either way, I can't seem to find any mention of it on my system leading me to believe it doesn't exist in OSX. I hope that's not the case...

 

[rbarris]

Anybody know if it's possible to force triple buffering within OSX for OpenGL games? In Windows there is usually the option of turning this on in the video card's control panel for OpenGL games (Direct X requires a 3rd party override utility to do so, but OSX doesn't use Direct X anyways).

Turning on vsync in Portal for example (mac version) halves the framerate whenever it drops below my monitor's 60hz refresh. This is generally the reason why people disable vsync but then you get torn frames every time the game isn't running at 60fps (for a 60hz display) even when it exceeds 60fps.

HW/OS specs please.

 

[unwinded]

Running Snow Leopard 10.6.4 on a MB Pro 13" 2010 with GF 320m. I would be curious if any model mac is capable of triple buffered vsync though

Just wanted to add that triple buffering works perfectly in Windows via DXoverrider from riva tuner and also I read some posts on the steam forum indicating it might not be possible at all in OS X but nobody is sure.

For a good overview of triple buffering, check this out:

http://www.anandtech.com/show/2794

Basically with vsync enabled, if performance dips below your monitor refresh then framerate drops to half your refresh (60 to 30fps and if the actual framerate is lower than 30fps it drops to 15fps, etc). Triple buffering prevents this from happening without having to turn off vsync and playing with torn frames.

Using Portal for example, performance seems to dip to around 45fps when looking through portals. With vsync enabled, it'll drop to 30fps. With vsync off it will remain at 45fps but have badly torn frame. With triple buffered vsync it would remain at 45fps without torn frames. The framerate also exceeds 60fps at many points which will cause torn frames without vsync, preventable if triple buffering was being used

 

[rbarris]

Just to be clear, have you installed the Snow Leopard Graphics Update?

 

[unwinded]

Yep, installed the SN graphics update too. (Which noticable increased FPS)

After doing some more reading it sounds like some games (like WoW which i do not play) have an option for triple buffering so it is possible. Now if there is a way to force it on all the time for games, that would be ideal. There is a definite performance hit running steam games under OS X but I'd be willing to put up with it if it meant no torn frames