Alright, the 4870X2 just came out and thinking to buy 2 of these bad boys. Is it going to be worth it??? I've been waiting, my free (I won it from a LAN tournament) x38 mother and E8400 has been sitting in its box and it has never been opened yet.
I wouldn't. It seems like, for now, you have too much trouble with being CPU bound, even at ridiculous resolutions.
Depends on resolution, no? I got the impression that crossfire won't be of much use unless you're using a 30" display, but there's some performance gains to be had if you do. edit: just noticed a Cdn. store with 4870x2s ($625) http://www.extreme-pc.ca/showproduct.asp?productid=372405
I wouldn't attempt it with anything less than a 1000 watt PSU. And even then, some reviews show the 2 x 4870X2 GPU solution not scaling much better than a single 4870 X2, and in some cases it decreases performance.
