the radeon hd 3850 is faster than dual 2600xt cards and can run comfortably with a smaller power supply (350-400w). tom's benchmarks
the radeon hd 4670 is faster than the hd 3850 with new drivers but a bit noisy. xbit benchmarks
hd 3850, $70 before $15 rebate
hd 4670, $76 before $20 rebate
I am in the process of creating a new gaming rig and am right now torn between two cards. For whichever one I would choose, I would buy 2 of them and crossfire them for the best graphical output. However, I am on a fairly restricted budget. The two cards are as linked. The first one has a much higher memory clock and an hdi adpater, but it is only 256. The second is 512, but is 800mhz slower in the memory clock category. I am trying to find out which on the cards is better and what is more important memory clock, or mhz.