What are your system specs?And which PSU do you have?
Some cards will CF on a 600W PSU !
A quality 850W Can handle most of them.
Mobo: MSI 790FX-GD70
CPU: 955 BE @ 3.8g
RAM: OCZ AMD Black Edition 4GB (2 x 2GB) 240-Pin DDR3 1600 SDRAM DDR3
Vid: HIS iceq4 turbo 4870 1g (790mhz gpu, 1100mhz memory)
PSU: COOLER MASTER Silent Pro 600 RS-600-AMBA-D3 600W
HDD: SSD - OCZ vertex turbo 60g, 140g raptor
OS: win 7 32 bit
I was looking at the new directx 11 cards, and the high-end ones (5870) seem to draw a LOT of power