Hi guyz ^^ ive been making some threads lately.. and thanks for all the great help! Seems like im going for a i5.. and mabye 2 5850 in crossfire, but i really dont know how that will work out with the p55 chipset.. anyone got some bench's on that setup? ^^
P55 only has 16 PCI-Express lanes, so if you're running in x-fire, they'll both be running at 8x. Not sure what an impact that will have, but like The Razman said, you really need to be looking at an LGA1366 CPU and mobo if you want to employ a multi card setup unimpeded. X58 supports upto 32 lanes.
What he said, plus why not just pick up a single 5850 or 5870 and drop a second one in later if you need it.
A single 5850 is sufficient for almost anything, I am not sure why you would want more than one. However if you do there should be no problems with the 8x/8x PCIe 2 connection of the P55. TechPowerUp have done some testing that suggests that even with a HD5870 there isn't a significant reduction in performance when the PCIe connection is reduced to as low as 4 lanes. Even 1 PCIe lane can do a respectable job of operating a graphics card.