> I have an XFX HD 4770 and am considering going to crossfire with another
> Do I need to get exactly the same model for the second card?
"CrossFire can be implemented with varying-GPU cards of the same generation
(this is in contrast to Nvidia's SLI, which generally only works if all cards
have the same GPU). This allows buyers who have varying budgets over time to
purchase different cards and still get the benefits of increased performance.
With the latest generation cards, they will only crossfire with other cards
in their sub series. For example, GPU in the same series can be crossfired
with each other. So a 5800 series GPU (e.g. a 5830) can run together with
another 5800 series GPU (e.g. 5870). However GPU's not in the same hundred
series cannot be crossfired successfully. (e.g. a 5770 cannot run with a 5870)"
You might want to do a little research though, on "microstutter", to see
if doing things like that has any side effects or not. I've never run
SLI or Crossfire here, and have no first hand experience with it. http://forums.extremeoverclocking.com/t299445.html