When using KDE4's Konsole with a bitmap (.pcf) font with the nvidia proprietary driver, text rendering is very slow. The problem is the XRenderCompositeText32() call in QX11PaintEngine::drawFreetype(), which is very slow due to (guessing from http://www.nvnews.net/vbulletin/showthread.php?t=125111) the fact that bitmap fonts are 1bpp and the driver doesn't accelerate those.
upstream bug report:
Created attachment 241271 [details, diff]
patch from upstream bug
Seems like upstream didn't apply the patch
(In reply to comment #2)
> Seems like upstream didn't apply the patch
Right, and we won't apply a patch that upstream rejected, sorry.