Money is not a concern as long i could get the best two cards fit in my case, i know Tri-SLI is the way to go, but my PC case is not big enough and i doubt any that any developers will utilize their engine to take advantage of 3 cards when paired together. So i stay with two card onfiguration.
My current system is:
Intel Core 2 Quad Q9450 2.66 GHz
Asrock X48 TurboTwins-WiFi
4GB DDR3 1066 MHz
Asus EAH 4850 512MB
Aerocool 750 Wat PSU
My requirements: My PC should be as quiet as possible, with my current specs, the system fan already running like crazy, especially after upgrading from 9600GT to HD 4850.
I will sacrifice a little bit of performance as long the cards run as cool as possible, thus without making my PC case stress with heats.
And of course the cards should be future-proof, it should be able to run games like Far Cry 2 at least 50fps.
There's no telling if the quad crossfire scaling will be better with the 4870x2 than it is for the 3870x2. We can only wait and see.
Also, if you don't overclock that CPU pretty hard, it's likely to bottleneck these extremely high-end graphics solutions.
Well, they claim the 4870x2 does not use a bridge chip, shares ram and act as a single gpu. If this is true, then it would scale as dual cf, and not quad cf, and thus perform far better than gtx280 sli. ATI/AMD may be blowing smoke though.