Phoronix: Hidden ATI Feature For Textured XRendering
Earlier this week we published benchmarks of the XRender extension using NVIDIA's latest beta Linux driver, which had a substantial performance boost thanks to Render improvements with this latest driver. One of the questions that have since come up is how ATI/AMD's binary Linux driver compares when using this X extension. Well, right now, it lags behind NVIDIA, but a Phoronix Forums member has discovered a hidden ATI Linux option that should yield XRender performance gains.
how does the hidden XRender extension affect every-day usability and performance? I plan on turning it on when i get home, but I'm not sure what to look for in terms of benefit.
Wow - you're right - gtkperf benchmark is much worse with the Textured options on.
fglrx with Textured2D TexturedXrender TexturedVideo on: 151 seconds
fglrx with only XAANoOffscreenPixmaps on: 25 seconds
open source radeon with XAA: 28 seconds
open source radeon with EXA: 65 seconds
The vast bulk of the difference in fglrx tests was the circles test: 123 seconds with Textured options on, 1 second without. Other times were only very slightly slower.
I am currently running the 8.42.3 release of the ATI fglrx driver and I am experiencing quite a 2D slowdown. If I remember correctly, it has to do with enabling the compositing extension when not using AIGLX.
Regardless, I wonder if enabling this option will help 2D performance?
I have enabled this option, and it has improved performance tremendously for me. I was previously using the radeon driver, because fglrx didn't give acceptable 2d performance. With this option enabled, most of the issues are gone.
I've noticed gtkperf isn't really a very good indicator of performance, probably because it hammers away at a single operation at a time, rather than the mixed operations common in a normal environment.
It's not nvidia, but it's better than anything for my x1600 I've seen yet.
I'm on a X1300 mobility (Thinkpad T60, Core duo 1.8GhZ), and Textured2D seems to make a huge difference with 7.11. As long as I have benn using 8.41+ , I've experianced noticably degraded 2D performance, especially with everything mozilla. I didn't run any benchmark, but redrawing on desktop switching, drawing of popups etc. is much faster and smoother after activating Textured2D. TexturedXRender degrades the visual quality though (visible e.g. with KDE desktop icons), so I deactivated it again. Still, with Textured2D, my desktop is faster than ever before, and I didn't observe any instabilites so far
It would be interesting to know which hardware people with different results have, I would expect the performance and stability of this option to be very dependend on the GPU type (which most likely also is the reason while it is still undocumented).
I'm on a Radeon 9800 pro with the 7.11 fglrx driver, and enabling the Textured options, slows down everything. Moving windows on my xfce4 desktop (Xubuntu 7.10) for example, is an affront to my eyes. I used 'x11perf -move' to check and got
12000 reps @ 0.4763 msec ( 2100.0/sec): Move window (4 kids)
12000 reps @ 0.4854 msec ( 2060.0/sec): Move window (4 kids)
..
..
with Textured options on.
Any other x11perf test approved this mayor slowdown.
I also noticed wrong colors while using midnight commander in a terminal (got yellow and red, instead of blue and white) with Textured options on.
The "x11perf -move" test gives interesting results: although the numbers are much lower with textured options on, they don't decrease as significantly as the number of "kids" increases:
I expect TexturedXrender is only being designed for the newer R500 and R600 cards, where TexturedVideo is already used.
And it's always possible, that for a simple task, getting the CPU to tell the GPU to do it and then wait for the GPU to finish, will take longer than the CPU just doing the task itself.