Phoronix: Does Compiz Still Slow Down Your System?
There have been a flurry of comments this week following my post why software defaults are important and why in the Linux benchmarks at Phoronix.com the tests are most often carried out in their default/stock configurations: it's what most everyone uses. There have been comments by Ted Ts'o on file-system default mount options and whether they are sane or not in the non-enterprise distributions and others have questioned if defaults like Compiz on in Ubuntu by default makes sense. Does using Compiz still hurt your graphics performance?
If it hurts my 3D performance, I don't notice it, because I don't play demanding games. As for desktop usage, the r600c/g drivers have run Compiz with many effects enabled extremely smoothly (better than EXA) for a while now.
I have noticed too that Compiz mostly doesn't decrease performance. However, KWin does and the difference can be huge. It would be cool if you made an article that compares:
- Gnome without Compiz
- Gnome with Compiz
- KDE without KWin
- KDE with KWin
Glxgears is not a benchmark, but it does stress the copying. The terrible performance of the PCI card and the huge hit it gets from compositing make me believe that the problem is in the extra blit, caused by the compositing environment.
If I recall correctly (it's all muddy and I'm not a developer), the extra blitting causes a large hit with Mesa drivers in general. This is also why the KMS path was so much slower when it was first introduced, right?
The binary blobs have it really well-optimised.
That's why a check with a non-compositing window manager would be useful.