Best 4-Bay (and One 8-Bay) NAS Compared: Synology DS925+ vs UGREEN, ASUSTOR, TerraMaster, Ubiquiti and QNAP

Price: who gives you the most for the money

Only four of these seven have confirmed prices, which immediately shapes the value argument. The Synology DS925+ at $639.99 is the cheapest known quantity here, and the UGREEN DXP4800 Pro at $679.99 sits just $40 above it — yet that $40 buys a 13th-gen Core i3 and a 10GbE port the Synology simply does not offer. On raw spec-per-dollar the UGREEN wins that duel outright.

At the top of the confirmed pricing, the TerraMaster F4-425 Pro ($799.99) is the most expensive four-bay in the group and still stops at dual 5GbE, while the Ubiquiti UNAS Pro 8 ($799.00) asks a dollar less and gives you eight bays, two NVMe cache slots and three 10G ports. If your yardstick is capacity and ports per dollar, Ubiquiti is the value champion of this line-up; if it's CPU per dollar, it's the DXP4800 Pro. The ASUSTOR AS6804T, UGREEN DXP4800 Plus and QNAP TS-h465 all have unconfirmed pricing, and in the QNAP's case the review is explicit that value is impossible to judge at announcement.

Networking: the 10GbE divide

This is the cleanest split in the whole comparison. ASUSTOR's Lockerstor 4 Gen3 wins on sheer network capacity with dual 10GbE plus dual 5GbE — described as exceptional for a four-bay chassis, and more than any rival here. The UNAS Pro 8 is the runner-up with three 10G ports (two SFP+ and one multi-gig RJ45), remarkable for a file-serving appliance at $799. Both UGREEN units pair a single 10GbE with 2.5GbE, with the Plus explicitly bondable for failover or extra throughput.

At the other end, the DS925+ is the weakest-connected box in this group: two 2.5GbE ports, no 10GbE option and no PCIe slot to add one — a regression the review calls out against its own predecessor. Worse, its quoted 522/565 MB/s throughput outruns what those ports can carry, so you cannot reach the performance you paid for. TerraMaster's dual 5GbE splits the difference: better than Synology's 2.5GbE and good for around 1010 MB/s aggregated, but it needs link aggregation to get there and still loses to the cheaper DXP4800 Pro's native 10GbE. QNAP's TS-h465 can't be scored here at all, as no networking details were published.

One caveat that applies to every 10GbE box here, and which the DXP4800 Plus review flags directly: you need a compatible switch and NIC to see the benefit, which raises total cost in a way Synology's and TerraMaster's buyers avoid.

Processing power: Plex, Docker and VMs

For anything beyond file serving, the UGREEN DXP4800 Pro is the clear winner: a 13th-gen Core i3-1315U with 6 cores, 8 threads and 4.5GHz turbo, described as offering real headroom for Docker and VMs. Its sibling, the DXP4800 Plus, is the transcoding-value pick — a Pentium Gold 8505 with Quick Sync that the review rates as far more than a file-serving chip — but it gives up two cores and two threads to the Pro.

ASUSTOR's Ryzen Embedded V3C14 is a clear step up from the previous Intel N5105 generation, but it loses the HDMI output and integrated graphics of the Gen 2 model, making it the worse choice of the x86 boxes for local playback and transcoding — an area where both UGREENs and QNAP's N150 (with integrated Intel graphics) have the advantage. TerraMaster's 8-core N350 has the highest core count of the non-UGREEN units and is a substantial step up from the N150 in the Plus model, which by extension puts it ahead of the QNAP's N150 too.

The UNAS Pro 8 is the outlier and the loser here: its quad-core ARM Cortex-A57 limits virtualisation and transcoding versus every x86 rival in this chart. And the DS925+ is explicitly not recommended for Plex transcoding — so if media work is the job, the two boxes with the most bays (Ubiquiti) and the best software (Synology) are both off the list.

Software: DSM's lead versus UGOS Pro's youth

Hardware is where UGREEN and ASUSTOR win; software is where Synology takes the round decisively. DSM and its app library remain the benchmark in the category, and DSM 7.3 plus the October 2025 policy reversal means third-party drives such as WD Red Plus and Seagate IronWolf are fully supported again — removing the single biggest reason to avoid the DS925+.

Against that, both UGREEN units carry the same caveat: UGOS Pro is immature, its native catalogue sits at around 29 apps, and UGREEN is new to storage, so long-term support is unproven. That is the trade-off in plain terms — the DXP4800 Pro beats the DS925+ on almost every spec, and the DS925+ beats it on every software metric.

QNAP's TS-h465 is the interesting middle ground: QTS is an established platform, and the move to expandable DDR5 makes QuTS hero's ZFS environment genuinely viable at this price tier — something no other unit here offers. Ubiquiti's UniFi Drive is a different proposition again, aimed at UniFi-estate file serving rather than the app-platform role DSM and QTS play.

Storage flexibility, memory and expansion

On NVMe, ASUSTOR wins on both count and quality: four PCIe 4.0 M.2 slots, enough for caching or a full all-flash build with no add-in card. Both UGREENs offer two PCIe 4.0 slots, and the DS925+'s two slots earn credit for being usable as cache or a full storage pool. TerraMaster technically offers three, but they are only PCIe Gen 3 x1 — which, as the review notes, undercuts the value of having three, and puts it last among the four-bay units on NVMe performance.

Memory is a three-way story. The DXP4800 Pro has the highest ceiling at 96GB; the Plus manages 64GB across two slots; ASUSTOR is the only unit here with ECC DDR5, though its 16GB arrives as a single SO-DIMM and runs single-channel until you add a second. TerraMaster also ships 16GB pre-installed — more than either UGREEN's 8GB out of the box — but its single slot caps out at 32GB and any upgrade wastes the bundled module. The UNAS Pro 8's 16GB is reported as non-upgradeable, the only unit here with no memory headroom at all.

For bays and total capacity, Ubiquiti's eight bays double every rival in this group, but Synology answers with the DX525 expansion unit, scaling from 96TB across four bays to 216TB across nine — the only unit here with a stated expansion path. Neither the ASUSTOR nor the UGREEN Pro has a PCIe expansion slot, so both are fixed at purchase; the UNAS Pro 8 counters with support for hot-swappable redundant 550W power modules, though the second module is reportedly sold separately.

Verdict: which one should you buy?

Best all-rounder — UGREEN NASync DXP4800 Pro (4.2). The highest-rated box here, and at $679.99 it delivers a 6-core/8-thread Core i3, 10GbE plus 2.5GbE and PCIe Gen 4 NVMe for $120 less than the TerraMaster and Ubiquiti. Accept UGOS Pro's thin app catalogue and it's the spec winner.

Best for software and long-term trust — Synology DS925+ (3.5). The cheapest confirmed price at $639.99, the best OS in the group and third-party drive support restored. Buy it if DSM's app library and Synology's track record matter more than ports, and if you are not doing Plex transcoding.

Best for fast networking and all-flash builds — ASUSTOR Lockerstor 4 Gen3 AS6804T (4.0). Dual 10GbE, dual 5GbE, four PCIe 4.0 M.2 slots and the only ECC memory here. Skip it if you want HDMI-out or local playback — the UGREENs win there.

Best capacity per dollar — Ubiquiti UniFi UNAS Pro 8 (4.0). Eight bays, two NVMe cache slots and three 10G ports for $799, ideal as a rack-mounted file server in a UniFi setup. Don't buy it for VMs or transcoding; its ARM chip can't match any x86 rival here.

Best Quick Sync value — UGREEN DXP4800 Plus (4.0), if it lands below its Pro sibling; best for ZFS fans — QNAP TS-h465 (3.5), the only unit offering QuTS hero, but wait for final specs and pricing. The TerraMaster F4-425 Pro (3.5) is the hardest to justify: it has the most cores of the Intel boxes and 16GB included, but at $799.99 with no 10GbE and Gen 3 x1 NVMe slots, the cheaper UGREEN Pro undercuts it on almost every front.