A:Answer The WD Black is a 6 Gb/s SATA hard drive. That would be 6000 Mb/s. It also spins at 7200 RPM. Some of the less expensive drives spin at 4800 RPM, so loading files will be slower on those (4800 RPM) drives. This drive also has 64 Mb of cache. Not sure about other WD drives, but I believe the 2.5" drives usually have less cache than the 3.5" drives. If you go for a 3.5" drive, make sure you have a 3.5" drive bay to put it in. One thing that makes the black drives more expensive is the longer warranty and longer estimated MTBF. That won't directly affect gaming, but adds to the cost.