Sad to say, but my Pegasus 2 R4 is filling up fast. (I guess that's good as i'm getting work ) Needless to say I need more hard drives. I want something 3/4TB in storage. They recommend Seagate Barracuda 4TB drive but when I search the model number (ST4000DM000) it comes up as only a 5900 RPM drive. Does that sound right. Seems to slow. My drive shipped with Toshiba's DT01ACA200, but there only 2TB each... Any advice would be appreciated. Thanks as always!