they are ALL the same. Anything over 20 bucks will perform as good as anything else.
all video cards do is pump the image to your monitor. They will not speed rendering or anything up. That work is done by CPU, memory and hard drive.
There are pci cards that will accelerate mpeg2 encoding, but again your video card has nothing to do with that.
The only thing fancy cards are good for is games and CAD. if you don't play games, buy a 50 quid card and spend the other 50 quid on a bigger hard drive. you won't regret it.
AMD Athlon 1700 (@2200mhz from 1466 sod the noise!) - 768mb pc3200 - 200GB Maxtor - Pioneer 106 - GF4 Ti4200 - twinhan/visionplus pci dvb-t - random pci analogue tv tuner - A7v600-x (to replace the a7n8x-d that died...) - random 17\" CRT
Sony STR-DE425 & Eltax c205s;
xBox w/20GB HDD- executer 2.3b;
xBox - standard;
Konica/Minolta dimage z10 w/2x512mb SD;
A silly amount of Cat-5 and usb cables