Ok so i have a acer aspire x1800. It's a slimline pc and has a 220w power supply. I'm looking for a card that is low proffie and can play games like half-life 2, team fortness 2, Killing Floor, stalker, Left for dead 2, at high settings 1024x768 and higher.
Windows 7 Home Premium 64-bit
Intel Pentium E5400 2.60GHz
2.0GB Samsung Single-Channel DDR2
Geforce 7100/ nforce 630i
320GB Hitachi SCSI
ATAPI DVD A SCSI Cdrom device
Your PSU is very low power. Both of those cards are as well but you still may be pushing it too far so don't be too surprised if it doesn't work. Of the two cards the HD5570 is better like AMAN says and they use basically the same power so it would be the way to go.