On Mon, Nov 28, 2011 at 3:33 PM, Element Green <[email protected]> wrote: > Hello, > I happened upon this thread when searching for information on slow > performance with Kicad and the open source radeon driver. > http://lists.x.org/archives/xorg-driver-ati/2011-August/021077.html > I have a ATI/AMD HD 5800 series video card in my laptop. I've also been > rather impressed with the open source driver, even compared to Catalyst > (which seems to suffer from many problems, especially with gnome 3). So I'm > very keen on getting Kicad to be usable with it. > After doing a lot of profiling with sysprof, oprofile and gprof, I > discovered that the open source radeon driver works acceptably when the > radeon Kernel module is not loaded. I discovered this when I was trying to > switch back to the open source driver from Catalyst and there was an issue > with the Kernel module loading. > From what I can tell from /var/log/Xorg.0.log there is some rather > significant initialization differences when the radeon Kernel module has not > been loaded. I tried disabling dri and dri2 to see if they were the > culprit, but that makes Xorg non functional (weird square block for a mouse > cursor over a black or corrupted display). I also tried disabling many > other extensions and modules (Render, glx, Composite), but none of them > seemed to be causing the issue. > Does this lend any information in regards to what could be causing the poor > performance with Kicad? Any ideas what different code paths could be
When you don't load KMS, you disable acceleration so you are getting software rendering. Adding: Option "NoAccel" "True" to the device section of your xorg.conf should produce the same effect. IIRC, Kicad uses certain operations that are not accelerated which causes a fallback to software rendering. This ends up being slower than pure sw rendering due to ping-ponging between GPU and CPU memory and waiting for the gfx pipe to drain. Alex > responsible? From a rough view from "top" I can see that the CPU usage is > about 80% and 20% for Pcbnew and Xorg in the Catalyst and non Radeon kernel > module load cases (good performance cases) and 20% and 80% for Pcbnew and > Xorg in the normal radeon driver case (the poor performance case). So it > would seem that Xorg and friends are taking up more CPU (about 3 times as > much) in the poor performance case. > Best regards, > Element Green > > > _______________________________________________ > xorg-driver-ati mailing list > [email protected] > http://lists.x.org/mailman/listinfo/xorg-driver-ati > > _______________________________________________ xorg-driver-ati mailing list [email protected] http://lists.x.org/mailman/listinfo/xorg-driver-ati
