TerraMaster F4-421 Review 4-Bay NAS for SMB Users


TerraMaster F4-421 4-Bay NAS Management

After turning on the NAS, connecting it to your network, type in “start.terra-master.com” in your browser to bring up the Quick Installation Guide. We recommend using Chrome as we had a few issues with Windows 10 Edge.

Setup of the TerraMaster F4-421 is identical to the past 2-bay NAS units we have reviewed. Head over to F2-210 review for a complete write-up on setting up a TerraMaster NAS.

We will show a few screens that highlight the F4-421 user interface.

TerraMaster F2 421 TOS Desktop
TerraMaster F4 421 TOS Desktop

The main TOS Desktops is the same as the past reviewed units. This is still a major differentiator over solutions like FreeNAS. The TerraMaster desktop is much more user-friendly.

Here we see the hardware information for the TerraMaster F4-421. This includes the Intel Celeron J3455 SoC.

TerraMaster F2 421 Hardware Information
TerraMaster F4 421 Hardware Information

Here we see what a full RAID JBOD Volume looks like in the Storage Manager. We did note that when deleting a RAID, TOS did not show a pop-up asking to rekey in admin password to make sure that you wanted to delete the entire RAID as this will delete all data. Be careful here when changing RAID levels. That may be an infrequent exercise, but having a heavier prompt to stop accidental data deletion is welcome.

TerraMaster F2 421 RAID Setup
TerraMaster F4 421 RAID Setup

Applications available for the Terramaster F4-421 are also the same as previously reviewed units.

TerraMaster F2 421 Applications
TerraMaster F4 421 Applications

Next, let us take a quick look at the F4-421 specifications and continue on with testing.

TerraMaster F4-421 Specifications

Here is a table with the key specs of the TerraMaster F4-421:

TerraMaster F2 421 Specifications
TerraMaster F4 421 Specifications

One will note that the Intel Celeron J3455 is something that is well suited to power lower drive count RAID as we see here. We also wanted to point out the 4GB base memory with an 8GB expansion option for up to 12GB possible. We think most users will not run many applications on this NAS, but if you do the option to increase RAM is there.

Test Configuration

The platform that we use for the testing on all of our NAS testings consists of the following items.

This gives us a high-performance server/ workstation platform to test performance to the various NAS units we test.

Next, we are going to look at the performance of the TerraMaster F4-421 before settling on our final thoughts.


  1. Hi!
    It seems TerraMaster like to reuse the same backplane in several of their nas, and i saw a 4 bays model that had the backplane of the 5 bays model, hence you could dremel the front panel to use the fifth bay.
    Could you check if it is the case with this one? you could put a 2.5″ SSD inside the case to be used as a cache this way, without losing one of the 4 “official” bays… 🙂
    That would increase its value even more!


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