This thread is a little crazy... anyway, OP should at least work out which drives are 5400rpm and rule them out (WD Red, WD Blue). Regarding WD drives, they advertise Black as their performance desktop drive, so that is probably the one to go for. Check some reviews to compare the Barracuda Pro, but I believe the non-pro drives are all shingled now??? If so, I would stay away. The ones in external caddies are almost certain to be shingled. I don't know about the Enterprise grade data centre drives, but I would expect them to have firmwares that are better suited for a server than a desktop. Short version... just compare Barracuda Pro and WD Black... probably not much real life performance difference between them!