Improving QEdje and Qt performance with nvidia drivers.

Hey all,

You may have been following the buzz around bad 2D performance of nvidia-drivers, specially with KDE 4. Well, I found out that QEdje was running slower than it could on my machine due to the same reason.

Zack Rusin released yesterday a nice benchmark utility for Qt, QGears2, which I used to measure the effect of Lemma’s suggestion on KDE’s techbase.

My machine is a 2.4GHz Core 2 Duo / 2gb / nVidiaGeForce 8600M 256mb MacBook Pro, running Gentoo ~x86.

The first tests were conducted using:

  • Xorg-server 1.4.2
  • Xorg 7.3
  • nvidia proprietary drivers (nvidia-drivers) 173.14.12

The second test session were conducted after the following changes:

  • nvidia proprietary drivers (nvidia-drivers) 177.67 beta (I’ve unmasked them in Gentoo)
  • Added PixmapCacheSize and OnDemandVBlankInterrupts options to xorg.conf
  • applied InitialPixmapPlacement and GlyphCache hacks:
    nvidia-settings -a InitialPixmapPlacement=2 -a GlyphCache=1


Old setup:

  • -image –> 42 fps
  • -render –> 35 fps
  • -gl –> 396 fps

New setup:

  • -image –> 67 fps
  • -render –> 41 fps
  • -gl –> 476 fps

Let me know of your results.



emerge world reinstalling everything… not anymore :-)

I’m running ~x86 Gentoo here, eix-sync && emerge -Dav world every few days till something strange started happening. Portage wanted to reinstall everything, I mean, hundreds of packages to the same version as before, no new use, no new anything, just reinstall all packages for the pleasure of compiling and heating up my Macbook pro 🙂

Well, now I figured out that adding the “-u” flag to emerge restored the expected behaviour.

Maybe I was supposed to use “-u” since day one but the fact is I didn’t, and emerge worked fine until now. Anyway, if any of you face the same issue, try “-u”.