NVidia 7900GT performance problem solved...

[Tay Joshkin]

Thanks to a forum hosted at nvnews.net I found out that nvidia seems to struggle terrible with cleartype fonts (enabled "RGB Antialiasing" in KDE's Kontrol). They don't do the cleartype stuff in the GPU so it has to be done by the CPU. I still did not find out why my FX5500 does the job much better (but still slow).

Man this really sucks, I bought a high-midclass chip and can't use the 2D features I would like. Chip-horsepower without end but not able to make such simple stuff fast.

Therefor the only thing I can say: Hands off nvidia based cards if you would like to use KDE with cleartype fonts. If you don't game I guess an intel-chipset would not be bad :-/

Tay Joshkin