Does Compiz Still Slow Down Your System?
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.
Looking at those results, mostly on Nvidia side, makes me wonder how much efforts are being dedicated by Gallium3D team to improve performance on Gallium3D infraestructure.
Does anyone know if there is any work beeing done to improve Gallium3D infraestructure performance in the wild?
I didn't notice any special/cool patch for Gallium3D on 2.6.38. I could be wrong, and wish to Please correct me if i'm wrong....
Nice of you to cast doubt of FUD into conclusions based on your own article
No it doesn't. But it is annoying that desktop behavior (shortcuts, virtual screens and so on) changes with compiz and without it.
Now we know how to make Michael do new benchmarks
Does Metacity in Ubuntu use compositing? Because that's what made 3d apps slower under Compiz. If Metacity uses compositing as well now, then it's no wonder that the results are closer.
What happened to the Catalyst team starting around late 2009 and through 2010 to the present? Their driver stopped sucking. Maybe they got lucky and hired one or more brilliant minds.
Now if only we can make it not suck and make it open source. Damn. The numbers for r?00g are encouraging though.
FWIW, I have a PCI card (not express) in my computer, and there is a very apparent difference between fullscreen video (no compositing) and windowed video (composited environment) in KWin.
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
I bet the numbers will be very interesting.
I've made a quick check with glxgears:
KWin (+compositing): 240
KWin (-compositing): 440
KWin (+compositing): 2400
KWin (-compositing): 3050
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.