Hello everyone, As many of you know I used to have a 2008 Harpertown mac pro. Just recently got a refurbished 2.66(I know its slow, but its faster than my 8-core 2008!) nehalem mac pro. QUESTION: I just found on ebay for a buy it now price of 700.00 - a W3580 processor, the same one that one would pay 1200.00 for to upgrade on the apple store. CAN THIS PROCESSOR be used in place of the current 2.66? Given what we know about 4,1 mac pro - it has the same SMC, same firmware, same everything, so I don't see why this would be an issue. I did read that someone tried to upgrade the 2.26 processors and wound up buying a whole new board and stuff, but I was told that the single-quad cores are easier to upgrade and not much hassle is given towards them. So, if I were to BUY this processor(w3580) - Can I just remove the 2.66 and pop in the 3.33? I do know that the processors in these 4,1 quad-core units DONNOT have the heat spreader, but if I were to apply artic silver or the best thermal compound I can buy, WILL THIS WORK?? Can someone tell me yes for certain? I figure why wait when the price is right.. currently, have 6GB of memory 1066 DDR3, 4x1TB hard drives, dual superdrive(one being from my 2008 mac pro connected to the odd port), ati radeon 4870 HD. I mean, why should I spend 1200.00 extra from apple when I can just get the processor for 700.00 buy it now?