Dell 161-BCNH hard drive 24 TB 3.5" SAS 12 Gb/s 7200 RPM, Hot-Plug

With 24 TB on one drive, every bay in a server or storage array holds a great deal of data. That suits backups, archives, video surveillance and file servers, where capacity matters more than SSD speed. Fewer drives for the same capacity also means fewer occupied bays and more room for later expansion.

SAS is the interface of servers and storage systems and requires a SAS controller or backplane. A SAS drive cannot be connected to the ordinary SATA port of a desktop computer, but it fits servers whose drive bays are wired to a SAS backplane. The 12 Gb/s interface leaves the hard drive plenty of headroom, so the connection itself is never the limit.

7200 revolutions per minute is the usual speed for high-capacity server hard drives. The faster the platters spin, the sooner the read head reaches the data it needs, which shows in file servers and backup software where many files move at once. The manufacturer data gives no exact speed figures in megabytes.

512e means the drive physically uses large 4K sectors but presents 512-byte sectors to the system, so it also works with older operating systems and controllers. Hot-Plug lets you replace a failed drive in a running server, provided the server and bay support it, without stopping services.

Administrators of Dell servers and storage systems who need a high-capacity SAS drive for backups, archives or a file server; companies expanding an existing disk array; and IT teams choosing a spare drive by Dell part number so that the new drive matches the existing bay.