SATA3 drive at 5900rpm vs SATA2 drive at 7200rpm

What is your motherboard??

It doesn't have SATA3 support than there is no need to purchase a SATA3 drive. You will see no benefit on a SATA3 over a SATA2. You will get the better performance out of the SATA2 drive.

Are you sure the 2TB "Green" EARS drive spins at 7200 RPM? I though they were all 5400 RPM drives.

My motherboard is. The asrock 890x extreme 3 with USB and SATA 3.

If that is true then I would use a Seagate barracuda 7200.11, I think that there is a 2tb version isn't there?
My real question is whether a 5900rpm SATA3 driver is faster or slower than a 7200rpm SATA2 drive.

A 7200 RPM drive would be faster than a SATA3 or SATA4 or SATA100 5900 RPM drive. :-)

The sustained data rate is limited by the rate at which data moves between the cache and the platters, ie it is a function of the drive's RPM and platter density, not interface speed. Higher interface speeds will allow greater "burst" rates, but these would also be limited by the speed of the drive's cache memory, and also by seek times.

Thx