I can get a 5870 for £85, as opposed to a 7850 for £130, which one is better?
Btw, does a 5870 use 2 pci slots?
It only uses one slot.
The 7850 is significantly faster than the 5870, but then that 5870 is a lot cheaper. It's potentially good value if you can live with having an older card that uses more power and is probably noisier.