Intel X58 vs P55 Chipset: Crossfire and SLI Performance
 

Each platform was tested with a single GeForce GTX 260 896MB and Radeon HD 4870 1GB, and then with two of each in CrossFire and SLI, respectively. Our purpose here isn't to pass judgment on which single- or multi-GPU solution is superior, though. Instead, we're concentrating on how these graphics teaming schemes scale on each platform. These games were run at 1920x1080 with 4X antialiasing, 16X anisotropic filtering, and all their eye candy options cranked.


This one's just about a wash. With just one of either graphics card installed, the X58 and P55 are locked in a dead heat. The X58 does prove faster in Call of Duty and GRID with CrossFire and SLI, but only by slim margins.

http://techreport.com/articles.x/17513/8

it takes 2560x1600 to separate the men from the boys it seems


http://www.anandtech.com/cpuchipsets...spx?i=3634&p=9

If you're going to spend money on a VGA setup that can run games at 2560x1600, go for X58 and Bloomfield. For the other 99% gamers out there, Intel P55 and Lynnfield will be enough