Western Digital 400GB RE2 7200rpm 16MB Cache SATA 1.5Gb/s 3.5" Hard Drive - WD4000YR Western Digital Caviar RE2 WD4000YR 400 GB SATA/150 Hard Drive General Features: 400 GB formatted capacity 7200 RPM spindle speed 16 MB buffer Serial ATA (SATA) interface 150 Mbps maximum data transfer rate 8.7 ms average seek time 4.20 ms average latency 3.5-inch form factor Enterprise Features: rive error-recovery processes common to desktop drives. rone, multidrive systems such as rack-mounted servers or network storage.