The GMKtec NucBox G9 is a compact mini PC marketed as a 4-bay NAS solution. It packs four M.2 NVMe slots into a sub-1U chassis with an Intel N150 processor and 12GB of soldered LPDDR5, making it appealing for homelab enthusiasts who want dense SSD storage in a tiny footprint. At around $210, the specs-per-dollar ratio is compelling. On paper, it looked like the perfect low-power Jellyfin host. In practice, the fan developed bearing noise and died after less than a year of lightly loaded continuous operation, and the device had already developed a well-documented reputation for thermal issues before mine failed. The plastic chassis doesn’t help with heat dissipation, and the overall build quality feels budget-appropriate—fine at this price point, but not confidence-inspiring for 24/7 server duty. Not recommended for always-on use.

What It Is

The G9 is built around Intel’s N150 processor (Twin Lake), a slightly faster sibling to the popular N100. Four cores, four threads, 3.6GHz boost, 6MB cache. The 12GB of soldered LPDDR5 RAM is adequate for light server workloads.

The standout feature is storage density: four M.2 2280 slots in a chassis that measures roughly 146 x 100 x 39mm. Each slot supports up to 4TB drives, theoretically enabling 16TB of NVMe storage. Dual 2.5GbE Intel i226 NICs handle networking. There’s also 64GB of eMMC with Ubuntu pre-installed and WiFi 6.

At around $210, it’s aggressively priced for the feature set.

My Use Case

I ordered the G9 in May 2025 as a dedicated Jellyfin media server. The actual media library lived on my UNAS Pro via NFS—the G9’s job was purely transcoding and serving streams. I populated all four M.2 slots, though the drives were lightly utilized since storage was offloaded to the NAS.

The setup worked well for several months. Jellyfin ran smoothly, streams played without issues, and the compact form factor was… well, not exactly what I wanted for the homelab. I wanted a 1U fanless rackmount, ideally with 4 hot-swap drive bays, something that would be quiet, low-power, and utterly reliable. Instead, the G9 perched awkwardly on a shelf, driving the monitor and keyboard I used for on-site maintenance. But, the N150 handled transcoding adequately for my needs at first.

The Thermal Reputation

I learned after purchasing that the G9 had developed a reputation for thermal issues. Reviews from early 2025—including a particularly detailed one from Jeff Geerling in April—documented SSDs hitting 70-80°C, CPUs throttling under load, and systems rebooting during sustained benchmarks. This was all public knowledge by the time I ordered in May 2025, but I hadn’t done my homework.

I had the original version, not the Ver. 2 that GMKtec released later with improved ventilation. During normal operation, my unit seemed fine. I wasn’t pushing it hard—Jellyfin streaming from network storage isn’t a demanding workload. The documented thermal problems appear worst when all four NVMe slots are both populated and actively written to, which wasn’t my situation.

The Fan Failure

After somewhere between 7-12 months of continuous but lightly loaded operation, the fan developed bearing noise. The grinding progressed over a few days, then the fan died completely. Without active cooling, a passively-cooled N150 in an enclosed plastic chassis isn’t viable for sustained use.

I shelved the device rather than attempt a repair. The combination of cheap fans, documented thermal issues across the product line, and the general build quality made me skeptical that a fan replacement would provide much additional lifespan.

Build Quality Concerns

The G9’s chassis is plastic, including the panel covering the M.2 slots. Metal would have been a better choice for heat dissipation. The overall construction feels budget-appropriate—which is to say, not premium. When reviews describe the device as “an EZ-bake oven for SSDs,” the plastic enclosure is part of the problem.

For a $210 device, the build quality is acceptable. For a device intended to run 24/7 with four high-performance SSDs, it’s marginal.

Who This Might Work For

If you need a cheap, compact system for experimentation or intermittent use, the G9 could be reasonable. The specs-per-dollar ratio is good, and the form factor is genuinely useful for space-constrained setups.

But I can’t recommend it for always-on server duties. The thermal design is compromised, the cooling components aren’t durable enough for continuous operation, and the plastic construction doesn’t inspire confidence. When the fan died, I replaced the G9’s role in my setup with a beefier Proxmox host that I trust for long-term reliability.

Verdict

The GMKtec G9 is an attractively priced mini PC with a compelling feature set that’s undermined by thermal limitations and questionable durability. Mine lasted less than a year before the fan failed, and the documented thermal issues across the product line suggest this wasn’t an isolated defect but a symptom of an underbaked cooling design.

If you’re considering the G9 for a NAS or always-on server, look elsewhere. A slightly larger or more expensive device with proper cooling will serve you better in the long run.