it happens, that graphic processing is done by CPU (in absence of Graphic card) and it means, load on CPU extra.
and when u install graphic card, the GPU (Graphic Processor on Card) takes this extra load of CPU and makes application faster.
and yes GameGuru, (i have just quoted example, you are right though) FX wasnt as good as previous and current 6800.
Intel Core2Quad 2.66Ghz 12MB L2-Cache
4096MB DDR Kingston Hyper-X
XFX 9600GT AlphaDog
Seagate 2 X 320GB SATA2
LG L246WH Flatron 24"