The TerraMaster F4-220 a 4-bay NAS which features an Intel J1800 dual-core CPU, which is approaching mid-range by NAS standards. This is complemented with 2GB RAM and a single gigabit Ethernet port. These specifications seem perfectly adequate for a home/small office NAS, but as we’ll find out later, the hardware is only part of the picture. A significant benefit with buying off-the-shelf NAS devices is that they should come paired with excellent on-board software which can makes use of all that hardware. TerraMaster uses the “TOS” custom operating system, which appears to boot from an internal USB drive.