Quote: Originally Posted by alphanumeric
If its a 3.5 inch form factor drive its likely a 7200 RPM drive. If its a 2.5 inch form factor drive its likely a 5400 RPM drive. Desktop 3.5 inch drives are usually 7200 RPM drives while laptop 2.5 inch drives are 5400 RPM drives. Green is a power saving version, go Black for more performance.
Form factor has little to do with HDD speed. I've seen 5400 rpm 3.5" HDDs and 7200 rpm 2.5" HDDs. In the case of the WD Greens, rotational speed is supposedly 5400-7200 rpm, according to WD, but in actual practice, they probably spend most of their time around 5400 rpm if not spun down by the computer.
The Greens are OK for storage but lousy for the OS.