Originally Posted by ewildgoose
A while back I bought a 6600GT from Gigabyte because it was the only decent fanless card I could find. It has had continuous performance problems with 2D whenever anti-aliased fonts are enabled (it's not terrific when they are disabled either mind)
This has been a known bug for at least a year. It is still not fixed.
However, when you do not use the subpixel hinting (or set it to grayscale) it will work much better. This is under fonts -> antialias -> configuration.