%cpu and Xorg - Jaunty

Willy Hamra w.hamra1987 at gmail.com
Fri Apr 3 21:43:29 UTC 2009

2009/4/4 Mark Greenwood <fatgerman at ntlworld.com>:
> On Friday 03 April 2009 15:49:43 Dotan Cohen wrote:
>> > Without Desktop effects enabled and the new (today's) updates, Xorg seems to be behaving. If
>> > however I switch Desktop effects back on then my cpu usage goes back up.
>> As you have reproduction instructions, file it!
>> --
>> Dotan Cohen
>> http://what-is-what.com
>> http://gibberish.co.il
> I'm almost certain that this is a video driver issue. Are you using nvidia drivers? I am. I found two things:
> Disabling 'use Vsync' on the Advanced tab under Desktop Effects helped a little
> Also, I created /etc/modprobe.d/nvidia.conf which contains one line
> options nvidia NVreg_EnableMSI=1
> You need quite recent hardware for this to work, but it enabled 'Message Signalled Interrupts' for the nvidia driver (180.44), which stops it from sharing interrupts with any other hardware. You can find out f it worked by doing
> cat /proc/interrupts
> You should see
> 2294:        309        104   PCI-MSI-edge      nvidia
> (the numbers will be different).
> Please note, I don't know what effect this will have if your hardware doesn't support MSI. It may make it impossible for you to start KDE.. Anyway, it didn't cure the problem for me but it has helped reduce CPU usage of Xorg and kwin, and the desktop does feel a little more responsive.

i have a pretty recent hardware, and will try it out. i also use
nvidia, and i also have these problems. most notable when firefox is
running. if i have no browser open, KDE is real fast! but who lives
without a browser?
i'll share few things that helped improve the speed.
i added these to my xorg.conf under section "screen"
        Option         "RenderAccel" "True"
        Option         "DisableGLXRootClipping" "True"
        Option         "DamageEvents" "True"
        Option         "UseEvents" "True"

renderaccel and damageevents should be enabled by defaut, but i added
them to be sure. the ultimate improvement was caused by UseEvents.
this tells xorg not hang the computer when the nvidia driver is doing
something and waiting for it to finish it. instead, just keep working
normally till u get an event that the driver finished its work. or at
least something like it, lol.

Willy K. Hamra
Manager of Hamra Information Systems
Co. Manager of Zeina Computers and Billy Net.

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