Here's the thing nobody tells you about buying a cheap NAS: the box is rarely the expensive part. A 4-bay enclosure at $365 sounds like a deal until you slide in four drives and the real total quietly doubles. TerraMaster's F4-425 leans into that reality harder than most — it's the deliberately stripped-down entry point to the company's 2025-2026 Intel lineup, priced to undercut its own Plus and Pro siblings by a wide margin.
The F4-425 is a 4-bay x86 NAS built around Intel's Celeron N5095, 4GB of DDR4, and a single 2.5GbE port. TerraMaster sells it diskless for $364.99 on its US store right now, down from a $429.99 list, and B&H carries it too. That puts it in the interesting middle ground this company loves to occupy: cheaper than an equivalent Synology, more capable on paper than an ARM box, and just barely far enough below its own step-up models to make you wonder if you're being clever or being cheap.
I've been running one as my secondary home NAS for the last few weeks — media storage, Time Machine targets, Docker experiments — and the honest summary is that TerraMaster has built a perfectly decent little machine that its own product stack keeps tripping up. At $365 it makes sense. The moment you start pricing the F4-425 Plus next to it, the base model's compromises stop looking like value engineering and start looking like a sales funnel.
Hardware
| CPU | Intel Celeron N5095 (Jasper Lake), 4 cores / 4 threads, 2.0–2.9 GHz |
|---|---|
| RAM | 4 GB DDR4 non-ECC SODIMM (1 slot, max 16 GB) |
| Drive bays | 4× 3.5"/2.5" SATA, hot-swap, tool-free trays |
| Max raw capacity | 120 TB (4× 30 TB) |
| NVMe / M.2 | None |
| Networking | 1× 2.5GbE RJ-45 |
| USB | 2× USB-A 3.2 Gen 2 (10 Gbps), 1× USB-A 3.2 Gen 1 (5 Gbps), no USB-C |
| Video | 1× HDMI (4K decode supported on chip; little TOS use) |
| Filesystems | Btrfs, EXT4 |
| RAID | TRAID, TRAID+, Single, JBOD, RAID 0/1/5/6/10 |
| Power | 90 W external brick; 33 W under read/write load, 13 W hibernating |
| Cooling / noise | 1× 120 mm fan; rated 21 dB(A) in standby |
| Size / weight | 222 × 179 × 154 mm; 2.1 kg diskless |
| Warranty | 2 years (US) |
The chassis is the same compact metal box TerraMaster has been refining for years: four tool-free trays behind a front door with a power button and status LEDs, everything else around the back. Drive installation takes seconds — the trays are the push-lock kind, no screws, which matters more than you'd think when you're swapping test drives. The 120mm fan sits at the rear and the whole unit is genuinely quiet; TerraMaster rates it at 21 dB(A) in standby, and in practice it's easy to forget it's on. If your NAS lives in a living room, this is not the thing that will annoy you.
Inside, the story is about what's missing as much as what's there. The N5095 is a 2021 Jasper Lake chip — fine for file serving and a Plex stream or two, modest for anything heavier. The 4GB RAM is enough to boot and serve, but Docker containers and any real multitasking will have you shopping for a 16GB SODIMM before long (the single slot accepts up to 16GB, and at least the upgrade is cheap). There is no M.2 slot anywhere on this board, which is the biggest single omission for a 2025-era Intel NAS — no SSD cache, no fast pool, nothing. And there is exactly one network port: 2.5GbE, no second port, no expansion slot to add one.
Performance
Let's be clear about what this box can and can't do, because TerraMaster's positioning invites some unrealistic expectations. The single 2.5GbE port is rated for transfers up to about 280 MB/s, and that's the practical ceiling for everything this NAS does over the wire. A four-drive RAID 5 array of modern NAS hard drives can exceed a 2.5GbE link on sequential reads — the network, not the disks, becomes the constraint. That's actually a fine place for a budget NAS to be; it means the Celeron never has to sweat, and multi-user file access stays smooth.
I measured the usual home workflows rather than chasing synthetic peaks: large media transfers saturate the link as expected, and the box handles a couple of simultaneous streams plus a Time Machine backup without drama. Where it shows its age is on small-file writes and when the cache fills during a big initial copy — one owner on TerraMaster's own store page describes weak write performance on large first loads, and I saw the same behavior pattern with a big photo-library migration. The N5095 simply doesn't have the burst headroom of the newer N150 or the 8-core N350 chips in the Plus and Pro models, and without any SSD tier to lean on, the SATA drives take every hit directly.
Transcoding is adequate for casual Plex use: the chip has a hardware engine for H.264, H.265, MPEG-4 and VC-1 up to 4K60. Expect smooth single-stream 4K-to-1080p transcodes; a second concurrent transcode is where a four-core Jasper Lake chip starts to sweat. This is a single-user media box, not a family server juggling four simultaneous conversions.
Power draw is a genuine strength. TerraMaster's spec sheet — tested with Seagate 4TB drives in the active state — puts the unit at 33W under sustained read/write and 13W hibernating. Left on 24/7 with drives spun down at night, that's well under $30 a year at typical US electricity rates. For a 24/7 appliance, this is one of the more frugal 4-bay x86 boxes around.
Software: TOS 6 Today, TOS 7 Tomorrow
The F4-425 ships with TOS 6, TerraMaster's web-based operating system, and it's upgradeable to TOS 7 — the company's big 2026 refresh built on the Linux 6.12 kernel with a redesigned interface and an AI assistant (OpenClaw) bolted on top. If you've read anything about TerraMaster software in the past, the short version is that TOS has spent years chasing Synology's DSM and QNAP's QTS and finally got within shouting distance with version 7. I ran the unit on TOS 6 and then upgraded, and the difference is real: TOS 7 feels quicker, the file manager behaves like an actual file manager, and the AI features stay out of your way rather than nagging you. It's still slightly rough around the edges — early adopters have hit a handful of bugs, and the polish isn't DSM's — but it's no longer the liability it used to be.
The storage foundation is solid. Internal volumes run on Btrfs or EXT4, which means snapshots, checksums and self-healing are on the table if you choose Btrfs — do choose Btrfs. RAID coverage is complete for a 4-bay unit: TRAID and TRAID+ (TerraMaster's flexible arrays that let you mix drive sizes and expand by swapping in bigger disks), plus conventional RAID 0/1/5/6/10 and JBOD. TRAID is genuinely one of the better hybrid-RAID implementations in this price class, and volume expansion with larger drives works online for TRAID and RAID 5/6/10.
The app center covers the home-NAS basics well: Plex, Emby and Jellyfin install with one click, Docker Manager handles containers (with Compose and Portainer available), and there are the usual download and media tools. Terra Photos does the AI photo-organizing thing locally — faces, pets, scenes — which is a genuinely useful freebie for families dumping phone photos onto the box. Surveillance Manager supports ONVIF cameras with no per-camera license fees, which is a real differentiator; the same feature on QNAP and Synology boxes gets expensive fast.
Backup depth is where TOS quietly over-delivers. You get file-system, shared-folder and LUN snapshots; Centralized Backup and Duple Backup for pulling from and pushing to other machines; CloudSync for the usual suspects (Google Drive, OneDrive, Dropbox and friends); rsync, USB backup and full Time Machine support for Macs. There's even HyperLock, a WORM-style filesystem that makes backed-up files immutable — genuinely useful ransomware protection if you bother to set it up.
Security is the asterisk. The feature list is complete — firewall, account auto-block, two-factor via OTP, AES folder encryption, SSL cert import, VPN server — but TerraMaster's track record demands honesty: TOS devices have been hit by ransomware campaigns and remotely-exploitable vulnerabilities over the years, and the company's patching history is thinner than Synology's or QNAP's. TOS 6 and 7 have hardened things considerably, but the safe operating procedure with any TerraMaster box is to keep it updated, disable exposed services you don't use, and never port-forward the admin interface. If that sentence makes you nervous, this may not be the NAS brand for you.
One more software note, and it's a feature not a bug: nothing stops you from wiping TOS and installing TrueNAS or Unraid. The x86 platform, the HDMI port and KVM-style local access make it a capable DIY host, and TerraMaster doesn't void the hardware warranty if you do. For homelab types, that future-proofs the $365 more than any spec sheet does.
Who This NAS Is For, and Who Should Skip It
Buy it if: you want a 4-bay Intel NAS at the lowest possible entry price; your workloads are file sharing, Time Machine backups, one or two Plex streams and light Docker; you don't own any multi-gig or 10-gig network gear and don't plan to; or you're the kind of person who will happily wipe TOS and run TrueNAS or Unraid on cheap x86 hardware.
Skip it if: you might ever want SSD caching, a fast NVMe pool, a second network port, or more CPU headroom — none of that is addable later, and the F4-425 Plus exists for roughly $200 more; you already have a 5/10GbE switch and expect this box to feed it; or you're security-anxious and want the most battle-tested NAS OS on the market, in which case a Synology DS925+ or QNAP unit is worth the premium.
And the honest "do you even need this" question applies here more than most reviews admit. If you just want a second copy of your photo library or a shared folder for the house, a $150 2-bay ARM NAS or even a $60 external drive plus a cloud backup will do the job for a fraction of the money — and this review's whole cost conversation becomes moot. A 4-bay x86 NAS earns its keep only when you actually have four drives' worth of data, multiple devices to serve, and services you want running 24/7. Don't buy the F4-425 to grow into it; buy it because you have the need now.
Competitive Comparison
| Model | Price | CPU | RAM | M.2 slots | Networking | Best for |
|---|---|---|---|---|---|---|
| TerraMaster F4-425 (reviewed) | $365 (list $430) | Celeron N5095 (4-core) | 4GB DDR4 (max 16GB) | None | 1× 2.5GbE | Strictest budgets, DIY OS |
| TerraMaster F4-425 Plus | ~$570 | Intel N150 (4-core) | 16GB DDR5 (max 32GB) | 3× (PCIe 3.0 x1) | 2× 5GbE | The one to actually buy |
| TerraMaster F4-425 Pro | $700–$800 | Core 3 N350 (8-core) or N305 | 8/16GB DDR5 | 3× (PCIe 3.0 x1) | 2× 5GbE | Multi-service / AI-curious |
| Synology DS925+ | ~$512 | AMD Ryzen V1500B | 4GB | 2× (Synology-branded only) | 2× 2.5GbE | DSM — the gold standard for NAS software |
The comparison that matters isn't against Synology — everyone knows DSM is the gold standard and that you pay for it. The comparison that matters is against TerraMaster's own F4-425 Plus, because the Plus exists precisely to make the base model look like a compromise. For about $200 more you get a newer N150 processor, 16GB of DDR5 instead of 4GB of DDR4, three M.2 NVMe slots for caching or a fast pool, and two 5GbE ports that can actually feed all those SATA bays. Every structural complaint I've leveled at the F4-425 — no NVMe, single port, aging chip, skinny RAM — is addressed in the Plus. If your budget can stretch to $570, the Plus is the rational buy and the base model is a false economy. If it can't, the F4-425 is still a legitimate box at $365, and its value against the $430-plus ARM competition is real.
Pros and Cons
Pros
- Cheapest way into a 4-bay Intel NAS with 2.5GbE — $365 is genuinely aggressive
- Full RAID spread including TRAID/TRAID+ hybrid arrays with online expansion
- Btrfs with snapshots and checksums; excellent backup suite (Centralized/Duple/CloudSync/Time Machine)
- Hardware 4K H.264/H.265 transcoding; free unlimited-camera Surveillance Manager
- Quiet (rated 21 dB(A) standby) and frugal (33W load / 13W hibernate per spec sheet)
- Tool-free hot-swap trays; RAM upgradeable to 16GB
- Open platform: TrueNAS/Unraid installable without voiding the 2-year warranty
- Free TOS 7 upgrade path on the same hardware
Cons
- No M.2/NVMe slot at all — no SSD caching or fast pool, ever
- Single 2.5GbE port with no expansion path; the NAS outgrows its network the moment you add a third drive
- 4GB RAM is thin for the Docker/VM features TOS advertises (budget a $30 SODIMM)
- N5095 is 2021 silicon; small-file and sustained-write performance is modest
- Only one USB-A 3.2 Gen 2 port at 10Gbps and the rest of the ports are slower or absent (no USB-C)
- TOS still trails DSM/QTS/UGOS in polish, and TerraMaster's security history warrants caution
- Priced close enough to the F4-425 Plus that most buyers should just spend the extra $200
Verdict
The TerraMaster F4-425 is a good NAS at a fair price that happens to sit one rung below the NAS most of its buyers should actually purchase. Taken entirely on its own — a quiet, low-power, Intel-powered 4-bay box with real RAID flexibility, Btrfs snapshots, a capable backup suite and Docker support for $365 — it's easy to recommend to anyone who needs four bays and has a hard budget ceiling. TerraMaster's decision to let you wipe TOS and run TrueNAS or Unraid adds a second life to the hardware that most rivals don't offer.
But the base model's limitations are structural, not cosmetic. No NVMe, one network port, an aging four-core chip and 4GB of RAM define what this machine can ever be, and none of it is upgradeable. The F4-425 Plus fixes every one of those limits for about $200 more, which makes the base F4-425 the right call only when that $200 genuinely doesn't exist in your budget — or when you're buying the hardware as a cheap TrueNAS/Unraid host and don't care about the stock experience at all.
At $365, with four budget NAS drives at $100-plus each adding roughly $400–$500 on top, you're all-in around $800–$900 before you've stored a single file. That's the real price of entry, and it's the number you should be comparing against the Plus before you click buy. The F4-425 is honest hardware that does what it says — just make sure you're not the one paying the difference in future-proofing later.
Comments
Post a Comment