So, I have been trying to figure out if using a 6Gbps internal HDD would have any real benefit in an early 2009 Mac Pro as opposed to a 3Gbps one. I am interested in buying the 2TB WD Caviar Black and I can't decide if I should go for WD 2002FAEX which has a 6Gbps interface or the WD 2001FASS which has a 3Gbps interface. I looked around but can't find information on where the bottleneck would be. They are very close in price... and other specifications and I don't mind going for either, but would like to know if there is any real benefit in going for the 6Gbps one. Can anyone give me information on this, or point to somewhere that talks about this? TIA.