HGST aims to fill that space with the 6 TB Deskstar NAS. It falls in the same market category as the WD Red. However, the HGST Deskstar NAS drives have a 7200 RPM rating and the 5 / 6 TB variants come with 128 MB of DRAM cache. This is expected to make them perform closer to the Seagate Enterprise Capacity v4 and Enterprise NAS HDD drives. In the remainder of the review, we will try to determine whether that is the case.
via AnandTech