Created attachment 22941 [details]
Screensht of corruption
When running on recent kernel (2.6.28 and now 2.6.29-rc5, not verified with earlier kernels) X is slow and CPU-intensive for a lot of operations that worked smoothly with older intel driver, xorg server and kernel.
A sample are the enlightenment animations which previously used nearly-0% CPU time and now use 60% CPU (Xorg) and partially flicker.
In addition the bottom half of the display often suffers from corruption (e.g. partially covered by brown lines/areas) See attached screenshot. The corruption can usually be triggered by GTK comboboxes or menus.
Kernel is running with KMS disabled (KMS not working on my system, see #20115 for system details).
Created attachment 22942 [details]
Created attachment 22943 [details]
The screen corruption looks similar to the one described in bug 18503.
(In reply to comment #3)
> The screen corruption looks similar to the one described in bug 18503.
They are probably the same, note that I could take the screenshot with gimp without difficult (just a fullscreen screenshot, then extracting pertinent area)
For me corruptions are in range 640..1050px where top of display is at 0px.
So the slowness remains for this bug.
Seems to be exactly the same problem that I have with my 855GM card.
I often get screen corruption and X is quite slow.
I'm not 100% sure about this, but I think KDE/Qt is much more affected by the slowdown than gnome/gtk. Perhaps this might be helpful for someone.
Created attachment 24006 [details]
Created attachment 24007 [details]
2D performance for software fallbacks (which 8x does a lot of) should be much improved in master or the 2.8 RCs. Could you retest with that? kernel 2.6.30 is required, though
Unfortunately this bug was about two separate issues simultaneously, but I think both are fixed now.
Rémi reports that the corruption is fixed between 2.6.1 and 2.6.2.
The 2.8.0 driver has many sw fallback fixes beyond what 2.6.1 had, and I just pushed a performance fix to master for non-component-alpha text on 8xx on top of some general performance fixes for cairo. The 8xx render support should now be in better shape on 855 than it's ever been.
Author: Eric Anholt <email@example.com>
Date: Thu Jul 16 13:34:09 2009 -0700
8xx render: Add limited support for a8 dests.
This improves aa10text performance from 74k to 569k on my 855 laptop.
This also causes my 865 to hang on aa10text like it does on rgb10text,
thanks to actually hitting render accel.