I just snagged a nice 2.4 8-core 2010 Mac Pro with the intention of upgrading the bananas out of it as a screw you to the price of the nMPs. I've decided on the x5690 for the CPU and I've been reading a lot of posts and trying to soak up some info. The question I have now is do I buy a new pair off of Amazon: http://www.amazon.com/SLBVX-INTEL-X...?ie=UTF8&qid=1424906190&sr=8-1&keywords=x5690 or used from Ebay?: http://www.ebay.com/itm/Matching-Pa...407?pt=LH_DefaultDomain_0&hash=item234bd9d11f Since they are within $100 of eachother, it made me hesitate. Can anyone give me some guidance on which of these two would be the best? I'd like to buy the new procs, but the Amazon page is so devoid of information, it makes it feel too good to be true. Thanks for the help!