Toshiba DT01ACA200 2000GB internal hard drive (8.9 cm (3.5 inches), 7200RPM, 64MB cache, SATA III) (Personal Computers)
After my research, these sheets of price / performance reasons, like sold in complete NAS system. Therefore, even several bought for 24/7 use. So far no problem and completely satisfied. But those who value on very quietly plates should possibly. Wei