TerraMaster F4-425 Pro NAS

The F4-425 Pro is TerraMaster's attempt to push its four-bay line into prosumer and developer territory. The headline change over the F4-425 Plus is the move from a quad-core Intel N150 to an 8-core Intel Core 3 N350 that bursts to 3.9GHz, and on paper that's a meaningful jump for anyone planning to stack Docker containers, run a couple of VMs or tinker with local AI workloads. It arrives with 16GB of DDR5 already fitted, four hot-swap SATA bays, three M.2 NVMe slots and dual 5GbE networking, all running TerraMaster's new TOS 7 with an OpenClaw AI agent that turns plain-language requests into system tasks locally.

That's a genuinely ambitious package for a compact desktop NAS, and the target buyer is clear enough: the enthusiast or small-team developer who wants more CPU headroom than a typical entry-level box provides, plus enough SSD and network bandwidth to actually use it. Whether the $799.99 price and the $220 premium over the Plus model are justified is the real question, and that depends heavily on how much of the hardware's potential the chassis actually lets you reach.

Our assessment is that this is a strong core with some frustrating edges. The CPU and the pre-installed 16GB of DDR5 are the best part of the story, and dual 5GbE with a claimed 1010 MB/s via link aggregation is a sensible middle ground that will saturate most home and small-office switching gear. Three M.2 slots alongside four SATA bays is unusually generous flexibility for caching or a dedicated flash pool, and TerraMaster's data protection list — snapshots, WORM, AES-256 and ransomware detection — reads like a serious feature set rather than a checkbox exercise.

The problems are mostly about bandwidth and value. Those M.2 slots run at PCIe Gen 3 x1, which is exactly the kind of compromise that turns an impressive slot count into a modest real-world gain, and TechRadar's characterisation of the machine as "hamstrung by PCIe lanes" is hard to argue with. There's no 10GbE option, so the network ceiling is fixed unless you commit to aggregation. The single memory slot means the 16GB module has to be discarded to reach 32GB. The HDMI port feels like an afterthought, and there's no USB4 or Thunderbolt to offer a faster expansion path. Non-ECC memory is also a reasonable point of hesitation for anyone treating this as a serious data vault.

Two caveats on confidence: we're working from the published specs and third-party verdicts rather than our own bench time, and TerraMaster's pricing and bundles reportedly shift quickly, so the value calculation could move. As it stands, this is a capable, well-featured NAS that asks flagship-adjacent money while quietly limiting the components most likely to make it feel fast. Worth a look if the CPU headroom is what you need — worth a hard comparison against the cheaper Plus model if it isn't.