AMD scales better then Intel when using more then 4 to 8 cores. I've heard this from some people who where using both systems that where used in university and some applications. Intel is sticking on it's FSB limitation while AMD has it's own HT offering way more bandwith.

AMD also created a true Dual & Quad core, Intel instead 'sticked' a few together, it works tho but what do you prefer, something truely or something hacked up?