The TerraMaster F4-424 looks identical to the D8 Hybrid expansion unit at first look, which is due to the two using the same housing. This means that you have four 3.5-inch drive bays around the front, nothing much on the sides or bottom, with all the interesting bits being around the back. The drive trays are also identical, with the same tool-less design and lack of drive numbering.
As the F4-424 is a NAS you find the obligatory network connectivity which consists of two 2.5 Gbps Ethernet ports. You'll also find a single HDMI port—which currently only allows for command line output and can't be used for video playback or similar—one USB 3.2 Gen 1 (5 Gbps) Type-A and one USB 3.2 Gen 2 (10 Gbps) Type-C port here and a standard 12 V barrel jack for power the NAS. The F4-424 also sports a standard 120 mm cooling fan which is located next to the ports. Finally, there's a power button in the top left-hand side corner.
Popping the left side off the F4-424, we find a pair of M.2 slots, as well as a single SO-DIMM slot, which is populated by a 8 GB DDR5 4800 MHz SO-DIMM. Due to the F4-424 being built around the Intel Processor N95, the M.2 slots are limited to PCIe 3.0, and we're most likely looking at only two lanes per slot, due to the SoC only having a total of nine PCIe lanes, of which three are used up for the two 2.5 Gbps Ethernet ports and the SATA controller for the hard drives. This means that there aren't enough PCIe lanes left to allow for four lanes per M.2 slot. This is rather unusual, also where the reset button is located, but it does at least keep it out of sight, which means it makes it harder for someone to "accidentally" reset the NAS.
Unlike QNAP and Synology, TerraMaster has chosen not to use a USB DOM for the compressed operating system image, from which the OS is installed during the initial setup. Instead, as you can see on the picture above, TerraMaster is using a standard USB drive—albeit a very compact one—which sits in a standard USB port located next to the SoC heatsink. Installing the OS onto one of the user supplied drives from a USB storage device is par for course when it comes to consumer NAS devices, something we liked that Ugreen has moved away from and we hope to see more of the established players to take note of.
We should point out that just as the D8 Hybrid, there are space constraints in the F4-424 when it comes to installing SSD's, and we couldn't even use one with a 6 mm tall heatsink, as the side of the housing wouldn't fit back on. This seems like a major oversight by TerraMaster and it's something that really should be addressed, least not for the longevity of the SSDs. Note that both of the screws holding the SSD's in place are thumb screws, but they're so tiny that we'd prefer regular screws, especially as TerraMaster decided to go with flat-head screwdriver slots in the screws, rather than Philips screw heads or something else that allows for a good grip and torque. However, this is a fairly minor issue and can be easily resolved by swapping the screws.
The F4-424 supports up to four SATA drives, of which two are via the SoC and two via an ASMedia ASM1061 2-port SATA controller. TerraMaster officially supports SATA drives up to 22 TB as well as up to 4 TB NVMe drives.
The Power Adapter
The 12 Volt power brick is rated at a mere 2.5 A and 90 W, which is the same as the one supplied with the D8 Hybrid. Admittedly the Intel Processor N95 only has a 15 W TDP, which suggests that we're not looking at a very power hungry NAS, but more on that later.