Capacity: 3 TB Rotational Speed (RPM): IntelliPower Microsoft operating systems prior to Vista, 32-bit operating systems, and Mac systems prior to OSX 10.4 may not support volumes greater than 2TB. To recognize the full capacity of this drive, you may need multiple partitions. Check with the manufacturer to verify your system's compatibility. Interface: SATA3 Data Transfer Rate: 6 Gb/s Buffer to Host (max); 145 MB/s Host to/from drive (typical) Form Factor: 3.5 inch Read/Write: 4.4 Watts Standby: 0.6 Watt