Comments on: Make Metacity compositing smoother

By: Jeremy Visser

Jeremy Visser — Sat, 01 Nov 2008 01:00:13 +0000

I’d say that this I can confirm that this is definitely not a placebo, but that wouldn’t make sense.

Perhaps you are encountering a bottleneck elsewhere, or your video card physically cannot cope with compositing that fast.

I’m an NVIDIA user here, so I have plenty of GPU cycles to burn.

By: jeff

jeff — Sat, 01 Nov 2008 00:55:56 +0000

tried again with various values with gnome-display-properties; 58hz, 70hz, 85hz. No matter the refresh rate, and no matter if I run my “stock” metacity or the patched version, I can’t perceive the difference are you certain this is not a placebo effect? maybe I’d need slow motion to see a difference.

I do notice that windows seem to tear when you move them fast, but your latest comment seems to indicate this is a different issue (vertical sync?).

By: Jeremy Visser

Jeremy Visser — Fri, 31 Oct 2008 23:16:50 +0000

Jeff, I would say the fact that you're running at 58 hz is the problem. No matter how fast the compositor updates, if the display is only running at 58 hz (only 8 hz faster than the old slow compositing rate), you're not going to notice any difference. Best to run at 75 hz. Baptiste, indeed that is the case, and would be necessary for utilising vertical sync, which Metacity doesn't support (it suffers from tearing). However, I'm not a coder -- I just change little values in code, and if I'm lucky, it even compiles!

By: Baptiste

Baptiste — Fri, 31 Oct 2008 18:10:05 +0000

ideally it wouldn’t be hard-coded but off-course in sync with your monitor’s refresh rate,

By: jeff

jeff — Fri, 31 Oct 2008 12:59:46 +0000

strange. IANAD, but running metacity composite 2.24 with this patch did not seem to change anything perceived-performance-wise on my side, with an i915 and a regular LCD panel (which gnome says runs at 58 hz or something).