Mini PC Specs: Beelink Mini S12 (N95) & GMKtec NucBox K12 (Ryzen 7 H 255)
Quick reference spec sheet for both units. Specs sourced from manufacturer listings and independent reviews as of April 2026. Note that both vendors ship multiple SKU variants under the same model name — confirm your exact config at purchase.
Beelink Mini S12 — Intel N95 / 8GB / 256GB
Thin-client / light workload / low-power always-on box. N95 is Alder Lake-N, efficiency-core only, 10nm (Intel 7). Good for pfSense, Pi-hole, a Proxmox edge node, light media, or a cheap office PC.
CPU
| Spec | Value |
|---|---|
| Processor | Intel N95 (Alder Lake-N, 12th Gen) |
| Cores / Threads | 4C / 4T (no hyperthreading on Atom-derived E-cores) |
| Base / Boost | 1.7 GHz / up to 3.4 GHz |
| L3 Cache | 6 MB |
| Lithography | Intel 7 (10nm ESF) |
| TDP | 15W stock, configurable to 20W |
| Instruction Set | x86-64, AVX2 (no AVX-512) |
Graphics
| Spec | Value |
|---|---|
| GPU | Intel UHD Graphics (Gen12, 16 EU) |
| GPU Clock | 1.2 GHz |
| Display Support | Dual 4K @ 60Hz (HDMI 2.0) |
| API Support | DirectX 12.1, OpenGL 4.6, OpenCL 3.0 |
| Hardware Decode | AV1, H.265, H.264, VP9 |
Memory
| Spec | Value |
|---|---|
| Installed | 8GB DDR4 SO-DIMM @ 3200 MHz |
| Channels | Single-channel, 1 slot |
| Max Capacity | 16 GB (single SO-DIMM limit) |
| Upgradeable | Yes, user-accessible |
Note: A separate Mini S12 SKU ships with 12GB LPDDR5 soldered — that variant is not user-upgradeable. The DDR4 SO-DIMM version (matching this listing) is the one you want for flexibility.
Storage
| Spec | Value |
|---|---|
| Installed | 256GB M.2 2280 SATA III SSD |
| M.2 Slot | 1x M.2 2280, SATA only (not NVMe) |
| M.2 Max | Up to 2TB |
| 2.5” Bay | 1x 7mm SATA III bay (up to 2TB), cable + screws included |
| Total Max Storage | ~4TB (2TB M.2 + 2TB 2.5”) |
Gotcha: The M.2 slot is SATA-keyed, not NVMe. Don’t buy an NVMe SSD expecting it to work.
Networking
| Spec | Value |
|---|---|
| Ethernet | 1x 2.5GbE RJ45 (listing-dependent — some older S12 SKUs ship 1GbE) |
| Wi-Fi | Wi-Fi 5 (802.11ac), dual-band 2.4/5 GHz |
| Bluetooth | 4.2 |
Verify before purchase: Some Mini S12 SKUs (especially older N95 stock) ship with 1GbE, not 2.5GbE. The Amazon listing you referenced explicitly specifies 2.5G LAN. Check the spec sheet on the exact ASIN.
I/O Ports
- 2x HDMI 2.0 (4K @ 60Hz)
- 4x USB 3.2 Gen 2 (10 Gbps)
- 1x RJ45 Ethernet
- 1x 3.5mm combo audio (headphone + mic)
- 1x DC barrel jack (12V/3A)
- 1x CLR CMOS reset
Physical / Power
| Spec | Value |
|---|---|
| Dimensions | 115 × 102 × 39 mm (~4.52 × 4.01 × 1.54 in) |
| Volume | ~0.46 L |
| Weight | ~0.5 kg |
| PSU | 12V / 3A external brick (36W) |
| Cooling | Active fan + heat pipe + HDD heatsink |
| VESA Mount | Included |
| Features | Wake-on-LAN, Auto Power-On (contact Beelink for tutorial) |
OS / Warranty
- Ships with Windows 11 Home pre-installed
- Fully Linux-compatible (Ubuntu, Proxmox, pfSense all work out of the box)
- 1-year warranty from Beelink
GMKtec NucBox K12 — AMD Ryzen 7 H 255 / 64GB / 1TB
Serious homelab / workstation-class mini PC. Three M.2 slots, OCuLink for eGPU, dual 2.5GbE, USB4. This is Proxmox node, dev workstation, or small VM host territory.
CPU
| Spec | Value |
|---|---|
| Processor | AMD Ryzen 7 H 255 (Zen 4, rebranded 8745HS for export markets) |
| Cores / Threads | 8C / 16T |
| Base / Boost | 3.8 GHz / up to 4.9 GHz |
| L3 Cache | 16 MB |
| Lithography | TSMC 4nm |
| TDP Modes | 35W / 54W / 65W (configurable in BIOS) |
| NPU | Disabled on H 255 (full 8845HS has 16 TOPS XDNA NPU — this chip does not) |
| Instruction Set | x86-64, AVX2, AVX-512 |
Important: The “H 255” is AMD’s China-market SKU of the 8745HS. Boost drops from 5.1 GHz → 4.9 GHz, iGPU clock drops from 2700 MHz → 2600 MHz, and the NPU is fused off. If you need the NPU for local AI inference (Windows Studio Effects, Copilot+, ONNX), this chip will not deliver it — get the K8 Plus (8845HS) or a Ryzen AI chip instead.
Graphics
| Spec | Value |
|---|---|
| iGPU | AMD Radeon 780M (RDNA 3) |
| Compute Units | 12 CUs |
| GPU Clock | Up to 2600 MHz |
| Display Support | Quad 4K (8K via HDMI 2.1) |
| API Support | DirectX 12 Ultimate, Vulkan 1.3, OpenGL 4.6 |
| Hardware Encode | AV1 (hardware), H.265, H.264 |
Memory
| Spec | Value |
|---|---|
| Installed | 64GB (2× 32GB) DDR5 SO-DIMM @ 5600 MT/s |
| Channels | Dual-channel, 2 slots |
| Max Capacity | 96GB (AMD platform ceiling per reviews; some listings claim 128GB) |
| Upgradeable | Yes, tool-free access |
Storage
| Spec | Value |
|---|---|
| Installed | 1TB PCIe 4.0 NVMe SSD |
| M.2 Slots | 3× M.2 2280 |
| Slot 1 | PCIe 4.0 ×4 (full speed, primary OS drive) |
| Slots 2 & 3 | PCIe 4.0 ×2 each (~4 GB/s theoretical) |
| Max Per Slot | 8TB |
| Total Max | 24TB across all three slots |
Three M.2 slots in a mini PC is rare. For Proxmox ZFS mirrors or a Ceph OSD node in a homelab cluster, this is legitimately useful.
Networking
| Spec | Value |
|---|---|
| Ethernet | 2× 2.5GbE RJ45 (Realtek RTL8125BG controllers) |
| Wi-Fi | Wi-Fi 6E (MediaTek RZ616) |
| Bluetooth | 5.2 |
| Link Aggregation | Supported on dual LAN (LACP-capable switch required) |
Heads up for pfSense/OPNsense users: Realtek NICs, not Intel. They work in modern FreeBSD/Linux but some purists prefer Intel. Not a dealbreaker, but worth knowing.
I/O Ports
Front:
- 1x Power button (LED status)
- 1x CMOS reset
- 1x USB 2.0
- 2x USB 3.2 Gen 2 Type-A (10 Gbps)
- 1x USB 3.2 Gen 2 Type-C (10 Gbps, DP Alt Mode, PD)
- 1x 3.5mm combo audio
Rear:
- 1x HDMI 2.1 (4K @ 120Hz, 8K @ 60Hz)
- 1x DisplayPort 1.4 (8K @ 120Hz)
- 1x USB4 Type-C (40 Gbps, DP, PD)
- 1x USB 3.2 Gen 2 Type-A
- 1x USB 2.0
- 2x RJ45 2.5GbE
- 1x OCuLink (PCIe 4.0 ×4, for eGPU or external NVMe)
- 1x 3.5mm audio
- 1x Fan/RGB control button
- 1x DC input (19V)
OCuLink Notes
- PCIe 4.0 ×4 = 64 Gbps theoretical, ~50+ Gbps real-world
- ~65% performance gain over USB4 for eGPU use (review-tested with RTX 4070 Super: 91% GPU utilization vs 57% on USB4)
- Rear placement = cleaner cable management vs K8 Plus front-mount
- Requires OCuLink-equipped eGPU dock (Minisforum DEG1, ADT-Link adapters, etc.)
Physical / Power
| Spec | Value |
|---|---|
| Dimensions | ~168 × 118 × 80 mm (approx, based on 1.58L volume) |
| Volume | 1.58 L |
| PSU | 120W external (19V/6.3A) |
| Cooling | Vapor chamber + dual fan + copper heat pipes |
| VESA Mount | Included |
| RGB | Internal fan RGB, toggleable via dedicated button |
Thermal / Noise
| Metric | Value |
|---|---|
| Idle CPU temp | ~40-45°C |
| Load CPU temp | 94-95°C (within AMD spec) |
| Idle noise | 33 dBA (audible in quiet rooms) |
| Load noise (default) | 40 dBA |
| Load noise (performance mode) | 46 dBA |
| Idle power | ~11W |
| Max power | 90-105W |
Noise caveat: This is not a silent PC. If it’s going on a desk in a quiet home office, you’ll hear it. For a networking closet or homelab shelf, it’s fine.
OS / Warranty
- Ships with Windows 11 Pro pre-installed
- Full Linux compatibility (Ubuntu, Fedora, Proxmox VE all confirmed working — GPU passthrough works for Windows VMs)
- 1-year warranty from GMKtec
Side-by-Side Quick Compare
| Spec | Beelink Mini S12 | GMKtec K12 |
|---|---|---|
| CPU | Intel N95 (4C/4T) | Ryzen 7 H 255 (8C/16T) |
| CPU perf tier | Entry / low-power | Workstation-class |
| RAM | 8GB DDR4 (max 16) | 64GB DDR5 (max 96) |
| Storage slots | 1× M.2 SATA + 1× 2.5” SATA | 3× M.2 NVMe (1× x4, 2× x2) |
| Max storage | ~4TB | 24TB |
| Ethernet | 1× 2.5GbE | 2× 2.5GbE |
| Wi-Fi | Wi-Fi 5 | Wi-Fi 6E |
| USB4 / OCuLink | No | Yes (both) |
| iGPU | UHD (16 EU) | Radeon 780M (RDNA 3) |
| TDP | 15-20W | 35-65W |
| Idle power | ~6-8W | ~11W |
| Volume | 0.46 L | 1.58 L |
| PSU | 36W | 120W |
| Price tier | ~$150-180 | ~$600+ (64GB/1TB config) |
Use-Case Recommendations
Beelink Mini S12 — Grab it for:
- pfSense / OPNsense firewall (if 2.5GbE variant)
- Pi-hole / Unbound DNS node
- Light Proxmox edge/remote node
- Kiosk or thin-client duty at a client site
- Dirt-cheap dev sandbox
GMKtec K12 — Grab it for:
- Proxmox VE node with multiple ZFS-mirrored VMs
- Dev workstation with virtualization headroom
- eGPU gaming/ML rig via OCuLink
- Small-office NAS alternative (24TB in triple M.2)
- Anything where you need real multi-core throughput and 64GB+ RAM