The TerraMaster U12-500 Plus is TerraMaster’s serious-business 12-bay rackmount NAS, built around an Intel Core i7-1255U with dual 10GbE networking as standard — a specification that significantly outclasses similarly priced QNAP and Synology rackmount alternatives. Running TerraMaster’s TOS operating system, it targets buyers who want enterprise-class hardware at a more accessible price. Bare-chassis price is around $1,799. This TerraMaster U12-500 Plus review covers the hardware, software and value.
TERRAMASTER U12-500 Plus NAS Storage - 12Bay Core i7 1255U 10-Cores 12-Threads CPU, 16GB DDR5 RAM, Dual 10GbE Ports, 2U Rack Mount Network Attached Storage Peak Performance for Business (Diskless)
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TerraMaster U12-500 Plus at a Glance
| Component | Specification |
|---|---|
| Bay count | 12 bays (3.5″/2.5″ SATA HDD/SSD) |
| CPU | Intel Core i7-1255U (10C/12T, up to 4.7 GHz) with Intel Iris Xe Graphics |
| RAM (default + max) | 32GB DDR5 default (this unit ships at 32GB), expandable to 64GB |
| Network ports | 2x 10GbE RJ-45, 2x 2.5GbE RJ-45 (4 ports total) |
| USB ports | 1x USB 3.2 Gen 2 Type-C, 2x USB 3.2 Gen 2 Type-A |
| Max raw capacity | Up to 216TB with 12x 18TB drives |
| RAID modes supported | JBOD, RAID 0/1/5/6/10, TRAID (TerraMaster RAID), TRAID+ |
| OS / Software | TerraMaster TOS 6 (web-based, ZFS optional) |
| Approx price | around $1,799 (bare chassis, no drives, with 32GB RAM) |
Hardware & Performance
The U12-500 Plus is built around the Intel Core i7-1255U — a 10-core (2P+8E), 12-thread processor with Intel Iris Xe integrated graphics. That is a genuinely capable laptop-class CPU for a NAS, and significantly faster than the Celeron-class chips used in equivalent QNAP and Synology rackmount units. The Iris Xe iGPU brings Quick Sync hardware acceleration that is more capable than the older UHD Graphics 600 chips: H.265 4K transcoding is comfortable, and even AV1 decode is supported. This unit ships with 32GB of DDR5 RAM as standard, expandable to 64GB — substantial headroom for VMs, ZFS (under TOS 6’s ZFS option), Docker containers and demanding multitasking. TerraMaster’s hardware-per-dollar advantage is the U12-500 Plus’s clearest selling point.
Storage & RAID Options
With 12 hot-swappable bays the U12-500 Plus accepts 3.5″ and 2.5″ SATA HDDs and SSDs — up to 216TB raw with 12x 18TB drives. RAID options include the standard suite (JBOD, RAID 0, 1, 5, 6, 10) plus TerraMaster’s own TRAID and TRAID+ (similar to Synology’s SHR/SHR-2), allowing flexible mixed-size arrays with single or dual fault tolerance. TOS 6 also supports ZFS as an alternative to its default Btrfs/EXT4 layouts, bringing ZFS snapshots, deduplication and data integrity. Two PCIe expansion slots allow additional 10GbE, 25GbE or M.2 NVMe expansion. Multiple M.2 NVMe slots provide SSD caching directly without taking up bay space.
Software & App Ecosystem
TerraMaster TOS is the youngest of the major NAS operating systems and has historically had a smaller ecosystem than Synology DSM or QNAP QTS. That gap is narrowing — TOS 6 adds ZFS support, a refreshed UI, improved Docker support (TerraMaster Container) and a more capable backup application (TerraMaster Backup) that covers cloud destinations and client backup. Third-party app support is meaningful but smaller than QTS’s; first-party app polish is improving but still trails Synology’s. For buyers who can live with a less polished ecosystem, the hardware-per-dollar advantage is significant. For broader comparisons see our best NAS for small business guide.
TerraMaster’s strategy of supporting alternative operating systems is worth understanding. The U12-500 Plus’s strong x86 hardware can boot TrueNAS Scale, Unraid, Proxmox or any standard Linux distribution from USB or installed to drive, opening up an ecosystem that dwarfs what any first-party NAS OS offers. TrueNAS Scale in particular is a popular alternative for buyers who want ZFS with the most mature implementation, plus a strong Kubernetes-based application ecosystem. This flexibility is harder to access on Synology and QNAP units, which tend to integrate hardware and software more tightly. For buyers who want a mainstream first-party experience, TOS 6 is sufficient; for tinkerers it is a launching pad.
Networking & Throughput
The U12-500 Plus’s networking is the standout feature: two 10GbE RJ-45 ports and two 2.5GbE RJ-45 ports, for four wired connections totalling up to 25Gbps. Few competitors in this price tier offer 10GbE as standard, let alone dual 10GbE. Real-world sequential throughput from a healthy RAID 6 array easily saturates a single 10GbE link, and with link aggregation or SMB Multichannel multiple clients can each see 10GbE-class speeds. SMB 3.0 with Multichannel, NFS v4, iSCSI and WebDAV are supported. For 10GbE-equipped small offices this is one of the most capable NAS units available at the price.
Use Cases — Plex / Backup / Files
For Plex the U12-500 Plus is genuinely capable — the Iris Xe iGPU handles multiple simultaneous 4K HEVC transcodes comfortably, and 10GbE networking ensures the NAS can deliver high-bitrate content to multiple clients without strain. For backup it is excellent: 12 bays of capacity, TRAID+ dual-disk fault tolerance and ZFS as an option make it a strong long-term platform. For file serving the 10GbE networking and i7 CPU put it ahead of equivalent QNAP and Synology rackmount units. See our best NAS for backup for further comparisons.
Verdict
At around $1,799 (bare chassis, 32GB RAM) the TerraMaster U12-500 Plus is one of the strongest hardware-per-dollar NAS units on the market. The i7-1255U, dual 10GbE, 32GB of DDR5 and 12-bay capacity outclass equivalent QNAP and Synology rackmounts at the price. The TOS software ecosystem is the trade-off — younger, smaller and less polished than DSM or QTS. For buyers who prioritise hardware and accept TOS’s maturity gap, it earns a strong recommendation. See our best NAS for small business for further options.
Risk-tolerant buyers and self-hosters will find the U12-500 Plus particularly attractive — the powerful i7 and abundant RAM make it a credible host for alternative platforms such as TrueNAS Scale or Unraid via boot-from-USB or full installation, opening up an even richer software ecosystem at the cost of warranty support for software issues. Buyers comparing it against QNAP’s rackmount TS-1264U-RP should think carefully about priorities: TerraMaster brings significantly faster CPU and dual 10GbE networking, while QNAP brings redundant PSUs and a more polished software ecosystem; both are reasonable choices for different buyers. The U12-500 Plus is also notable for its quietness for a rackmount — TerraMaster’s fan profile is more conservative than typical enterprise gear, making it easier to deploy in semi-shared spaces. Compare further options in our best QNAP NAS roundup and best Synology NAS guide guides.
Frequently Asked Questions
Does the TerraMaster U12-500 Plus have 10GbE networking?
Yes — two 10GbE RJ-45 ports as standard, plus two 2.5GbE ports for four wired connections totalling up to 25Gbps. Few competitors at this price offer dual 10GbE.
Is TerraMaster TOS as polished as Synology DSM?
Not quite. TOS 6 is improving — it now supports ZFS, has a refreshed UI and better Docker support — but the app ecosystem is smaller than DSM’s and first-party polish still trails. Buyers gain hardware-per-dollar value in return.
Can the U12-500 Plus run ZFS?
Yes. TOS 6 supports ZFS as an alternative to the default Btrfs/EXT4 layouts, with snapshots, deduplication and data integrity features.
Is the U12-500 Plus good for Plex?
Yes, very. The Intel Iris Xe iGPU handles multiple simultaneous 4K HEVC transcodes comfortably, and the 10GbE networking ensures the NAS can deliver high-bitrate content to many clients.
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