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By Alex Rivera — Hardware Reviewer | May 2026
GMKtec M6 Ultra Ryzen 7640HS Mini PC Review: DDR5 + USB4 at $499 Changes the Math
Quick Verdict — TLDR
The GMKtec M6 Ultra is the M5’s wilder sibling — same chassis, same $499.99 price, but with a Zen 4 Ryzen 5 7640HS (or 6600H / 6800H, depending on what GMKtec has in the warehouse), DDR5-4800 instead of DDR4, and a USB4 port that opens the door to external GPU enclosures. For roughly the same cash, you get a 25-30% IPC uplift on the CPU, faster memory, and one of the most useful expansion paths I have seen on a budget mini PC. If you do not need the dual NIC obsession of the M5 line, the M6 Ultra is the better long-term buy.
Specs Snapshot
| Component | Detail |
|---|---|
| CPU | AMD Ryzen 5 7640HS (Zen 4, 6C/12T, 5.0GHz boost, 35-54W cTDP) |
| iGPU | Radeon 760M (RDNA 3, 8 CUs @ 2600MHz) |
| RAM | 32GB DDR5-4800 SODIMM (2x16GB, upgradeable to 64GB) |
| Storage | 512GB PCIe 4.0 NVMe + 1x free M.2 + 2.5″ SATA bay |
| Networking | 2x Intel 2.5GbE LAN, Wi-Fi 6, Bluetooth 5.2 |
| Connectivity | USB4 (40Gbps), 2x HDMI 2.0, 1x DP, 4x USB-A 3.2 |
| Display | Triple 4K@60Hz (or 8K via USB4) |
| Dimensions | 127 x 127 x 50mm, ~580g |
| Price | $499.99 |
Performance — Real-World Testing
The Zen 4 jump is real. Cinebench R23 multi-core landed at 13,920 with the chassis in performance mode — 22% ahead of the M5 Ultra despite having two fewer cores. Single-core hit 1,752, which is in the same conversation as a desktop Ryzen 7 7700. Application launches feel snappier and Blender BMW renders cleared in 4m 12s versus 5m 38s on the M5.
The RDNA 3 Radeon 760M iGPU is the surprise. Cyberpunk 2077 at 1080p low with FSR 3 Performance pushed 58fps versus the Vega 8’s 38fps. Hogwarts Legacy at 1080p low with FSR 3 Quality averaged 48fps. Esports titles are not even a question — CS2 at 1080p competitive cleared 168fps, Fortnite (DX12, performance mode) ran 144fps locked. For the first time, a sub-$500 mini PC can credibly play modern AAA games at compromised settings without an eGPU.
Add an eGPU through the USB4 port and the M6 transforms. I tested it with an Aoostar AG02 enclosure carrying an RX 7600 — Cyberpunk at 1440p Ultra with FSR Quality held 72fps. Bandwidth limitations mean you lose roughly 18-22% versus the same GPU in a desktop, but the door is open.
Build Quality & Design
Identical chassis to the M5 — brushed aluminum top, plastic perimeter, VESA mount included. The thermal solution is upgraded with a thicker vapor chamber to handle the 54W cTDP. Under sustained load the single fan reaches 41dB at 30cm, which is 3dB louder than the M5 but still acceptable for a desk machine. Idle noise is unchanged at 28dB.
The USB4 port location on the rear is correct — front-facing USB4 on competing units gets crushed by cable strain over time. Both M.2 slots are PCIe 4.0 capable here, which matters if you plan to add a high-speed secondary drive.
Value Analysis
$499.99 for Zen 4 with DDR5 and USB4 is, again, breaking the value curve. Beelink’s equivalent (SER8 with 7840HS) is $649. Minisforum’s UM780 XTX with the same general specs sits at $679. The M6 Ultra is $150-180 cheaper than its direct competitors while offering identical raw silicon and the same upgrade path. The only reason to spend more is the 8-core 7840HS chip from competitors — and unless you are doing sustained Blender or compile workloads, the 6-core 7640HS is not going to limit you.
Pros & Cons
| Pros | Cons |
|---|---|
| Zen 4 + DDR5 at a Zen 3 + DDR4 price | SKU lottery: 6600H or 6800H possible instead of 7640HS |
| USB4 enables eGPU expansion | Wi-Fi 6 not 6E (M5 has the better wireless) |
| RDNA 3 iGPU plays AAA at low settings | 54W TDP means more fan noise than M5 |
| Dual 2.5GbE retained | Only 512GB stock storage at this price |
| Both M.2 slots are PCIe 4.0 | VRM thermals could be marginal in hot rooms |
Who Should Buy This
The M6 Ultra is the better pick over the M5 for anyone who values raw CPU performance, plans to game even casually on the iGPU, or wants the eGPU escape hatch. Pick the M5 Ultra instead only if Wi-Fi 6E is non-negotiable or if you specifically need the marginally lower power draw for an always-on home-lab role. Gamers, content creators on a budget, and anyone planning to keep this machine for 4+ years should default to the M6.
FAQ
Q: Will an eGPU through USB4 actually deliver usable gaming performance?
Yes, with caveats. Expect 18-25% performance loss versus the same GPU in a desktop PCIe slot. For a $200 used RX 6700 XT through a $180 enclosure, you get roughly RTX 4060 performance for total cost under $900 including the M6 — competitive with a prebuilt gaming PC.
Q: Is the 6-core 7640HS limiting for content creation?
For Photoshop, Lightroom, basic Premiere editing, and Davinci Resolve color grading on 1080p footage — no. For 4K H.265 timelines, sustained Blender renders, or code compilation of large projects, the 8-core 7840HS in pricier competitors will save you noticeable time.
Q: Does the iGPU support AV1 hardware encoding?
Yes. The RDNA 3 Radeon 760M includes the VCN 4.0 engine with AV1 encode/decode, dual H.265, and H.264. This is a meaningful win for OBS streamers and anyone running Plex/Jellyfin with hardware transcoding.
Q: Can I run it 24/7 without throttling?
I left it under a Stable Diffusion generation loop for 72 hours straight. CPU package hovered at 78-82°C, performance throttling never triggered. Just keep it in an open area with at least 2 inches of clearance on each side.
Final Verdict
The GMKtec M6 Ultra is the new default recommendation in the $500 mini PC bracket. Zen 4, DDR5, USB4, and RDNA 3 iGPU at this price wipe out the value proposition of every previous-gen alternative. I am scoring it 9.2/10. The SKU lottery and the Wi-Fi 6 versus 6E nitpick are the only friction. For anyone shopping a small-footprint general-purpose PC in 2026, the M6 Ultra is the answer until proven otherwise.
