Will a Dual Xeon E5310 8MB cache LGA771 ( 8 Core total ) will be faster in multi thread apps then a single quad core QX6700. Because buying 2 Xeon will cost 200$ cheaper. Without taking in consideration power consummation.I searched around the web and i didn't find any benchmark ( lol ) and this is pretty much a random question since i am bored atm.

Edit:

Oh well i found a site that did benchmark with botch cpu but with like 1 year different, i dunno but the Qx6700 kick the Dual Xeon 5310 !
QX6700: http://www.gamepc.com/labs/view_co [...] 821E9A2240
Dual Xeon E5310: http://www.gamepc.com/labs/view_co [...] 55&page=11

I think for an optimally written piece of software the E5310 would be slightly faster, but for the majority of applications the QX6700 would be significantly faster. If you are running something like a server that runs completely independent threads, then the E5310 might be a little better. But for pretty much any desktop application, even threaded ones, I think the QX6700 would be faster.

Both systems will perform more or less the same because you have 2x1.6GHz quads vs 1x2.66GHz quads; they'll be both great and more or less perform equally well in multitasking and in multithreaded apps while the Q6700 will give you a much beefier performance in single threaded applications. So at the end, I'd go with the Q6700.

Also, don't forget the other costs involved with the LGA771 system, such as buying a dual-socket motherboard and buying tons of FB-DIMM RAM.