Reading through phoronix I ran across an article about NVIDIA’s updated driver release and some links to some forum posts about how NVIDIA’s 2D rendering performance has progressively gotten so bad as the Linux desktop had migrated towards more advanced rendering solutions like XRender (used a lot in KDE 4.x).
Some members have said that 2D software rendering is even faster than what the NVIDIA drivers with hardware rendering can do right now, giving an example of scrolling through an OpenOffice Impress wizard taking seconds to render (a freaking wizard scrollbar).
The problems seem to be focused on the 8000 and 9000 series of NVIDIA cards, that includes many many mobile users as NVIDIA shipped a huge number of the (now confirmed to be faulty) G84 and G86 chipsets in mobile devices over the last year or so.
As user in the phoronix forums had this to say on the issue:
Yes, I have 8600M GS in my laptop and have an extremely bad performance with Ubuntu 8.04. First of all it’s slow, especially text scrolling in gnome-terminal. When using Midnight Commander, trying to view/edit files is very painful. nvidia-settings -a InitialPixmapPlacement=2 (-a GlyphCache=1 doesn’t work for some reason, there’s no such setting in my case) helps with that, but somehow it manages to totally screw all the rest of my system, especially when I switch between windows. It’s as if active window has cached fonts and everything is fast, but as soon as I switch to another window all the caches are dropped and nvidia starts rendering it cold. Note that all of this happens even without compiz. Compiz makes it worse. Compiz+Emerald make it unbearable, the delays are two and more seconds, and what’s the most funny part, become noticeable without InitialPixmapPlacement=2.
For folks running into performance problems have your voice heard by NVIDIA by posting to the unofficial NVIDIA support forums. While NVIDIA hasn’t historically been very responsive to the Linux crowd (no significant income from that crowd) the hope is that the blast of bad press on the issue will get them to clean up those portions of the drivers and speed things up.
There does seem to be rumored light at the end of the tunnel in the form of some massive driver refreshes that folks think NVIDIA might push out to all platforms. This could be the result of the NVIDIA/AGEIA PhysX integration work that has been going on and the big Forceware 177.79 driver release coming to Windows, but it’s anyone’s guess as to the lag time that we will actually see before that work makes it’s way to Linux in the form of updated drivers from NVIDIA.