GMKtec NucBox M6 Ultra Mini PC AMD Ryzen 5 7640HS review

The M6 Ultra is a compact mini PC built around the AMD Ryzen 5 7640HS. That chip has six cores and 12 threads, boosts up to 5.0GHz and includes Radeon 760M integrated graphics. The machine ships with Windows 11 Pro. Owners report a clean Windows install and say Ubuntu runs without issue. That makes it a reasonable general-purpose desktop, a small Linux workstation or a homelab node.

The chip runs at 35W in Quiet Mode or 50W in Performance Mode, and the CPU TDP range is listed as 35W to 50W. You choose between lower noise and more sustained power. With six cores and 12 threads, it suits containers and a light VM or two alongside everyday work. Graphics come from the Radeon 760M, so there is no discrete GPU. The power supply is a 120W external DC adapter (19V/6.32A).

It has two SO-DIMM DDR5 slots running at DDR5-4800, and the listed maximum is 128GB. GMKtec sells it in 16GB and 32GB configurations, so the ceiling sits well above what ships. With that gap between the shipped configurations and the listed maximum, there is room to add memory later if your VMs need it.

Storage has two M.2 2280 slots, each listed for up to 8TB. The supplied SSD is PCIe 3.0 and comes in 512GB or 1TB. The research doesn't state the interface speed of the second slot, so check that before planning a fast second drive.

The M6 Ultra has dual 2.5GbE Ethernet, Wi-Fi 6E and Bluetooth 5.2. Two wired ports make it usable for separating management and storage traffic, or for a small router or firewall build. No 10GbE or SFP+ port is listed.

The port list is three USB-A 3.2 Gen2 (10Gbps), one USB 2.0, one USB4 that GMKtec calls full-function, one HDMI 2.0 (4K at 60Hz), one DisplayPort and a 3.5mm audio jack. HDMI and DisplayPort give two dedicated video outputs. OCuLink isn't listed.

GMKtec uses a dual-fan design with separate zones for the CPU and for the SSD and memory. Noise falls to 36.1 dBA in 35W mode. Owners describe quiet running during normal use and stress. They also report that the fan is clearly audible when gaming or doing heavy rendering. If you plan sustained heavy loads, expect to hear it.

Idle power is the weaker point. TechPowerUp measured an average of about 10W at the wall over 24 hours. Owners say idle draw sits toward the upper end of the mini PCs tested. Load figures vary by source: about 70W from Team Pandory, whose method isn't stated, and 90W at full load from Lon.TV. For a machine left on all day, the idle figure matters more than the peak.

Owners describe good value for money against the specifications. The research doesn't cover warranty length, BIOS update history or GMKtec's support record, so confirm warranty terms with the seller before buying.

This is a sensible pick if you want to start with a modest memory and storage configuration and expand later. The two SO-DIMM slots, 128GB ceiling and two M.2 slots support that. Dual 2.5GbE adds to the case for homelab use. If your priority is the lowest possible idle draw, or a silent machine under heavy sustained load, the owner reports point to compromises on both.