I am interested in using used Xeon CPU's in a dual socket motherboard, I don't do much gaming anymore my rig is now used more for machine learning. TheseE5-2683 v3 (ebay link) CPU's seem to fit the bill are used on ebay and seem strangely affordable($700 for the pair) for the amount of computing power they offer vs a 6850k. I have seen a bunch of CPU's on ebay with the "ES" in the title, which I guess means Engineering Sample (the ones linked do not) and are about 60% of the price without the ES. Are the CPU's linked the same as the ones from this spec sheet? It says a single CPU was MSRP $1800 Q3 2014 now they are ~$360 each on Ebay, I understand server hardware has a shorter life cycle but that is crazy. Are these the actually CPU or a strange version? How do I know I have the correct version?