A Perfect Fit for Mini PCs: 1.79W 10GbE SFP+ in a Single M.2 Slot
In a nutshell: The LEKUO MR27F12 is a compact M.2 2280 network adapter with a single 10GbE SFP+ port. With typical power consumption of just 1.79W under 10GBASE-R full load, a fanless design, and a net weight of only 53g, it brings 10GbE connectivity to compact PCs, NAS systems, and industrial computers. The M.2 main card installs in a compatible motherboard slot, while a 20 cm flexible cable connects it to the SFP+ daughterboard mounted at the chassis bracket.
1. Key Specifications at a Glance
2. How Can a 10GbE Adapter Consume Just 1.79W?
10GbE network adapters are often associated with high heat output, large heatsinks, small cooling fans, and sometimes external power supplies.
The MR27F12 takes a different approach. One important factor is its SFP+ fiber-optic interface.
With 10GBASE-R, the network controller handles digital signaling and works with the optical transceiver, which performs the electrical-to-optical conversion. Unlike 10GBASE-T copper Ethernet, this design does not require the same type of higher-power PHY circuitry used to drive 10Gbps signals over copper cabling.
Compare two LEKUO M.2 10GbE solutions:
- 10GBASE-T copper version: 2.5W typical
- 10GBASE-R SFP+ version: 1.79W typical
That's approximately 28% lower typical power consumption for the SFP+ solution.
Power consumption also varies with link speed:
- 10G (10GBASE-R): 1.79W under full load
- 1G (1000BASE-X): As low as 0.29W
Low power consumption isn't just an energy-saving bonus. It's an important factor in making a compact M.2 design practical. M.2 slots have limited power delivery capacity, so a low-power architecture is particularly valuable when designing a 10GbE adapter that doesn't require an external power supply.
3. Can It Stay Cool Without a Fan?
Low power consumption brings another advantage: no cooling fan is needed, and no dedicated airflow path is required for the adapter itself.
We used a thermal imaging camera to measure the MR27F12 under full-speed network traffic.
Measured results:
- Central temperature: 48.5°C
- Maximum temperature: 49.0°C
- Ambient temperature: 23.6°C
A maximum measured surface temperature of 49°C indicates moderate heat under the tested conditions. Actual component temperatures and thermal limits may differ, but the results demonstrate the thermal performance of this fanless design in our test setup.
The fanless design also eliminates three common concerns:
- No fan noise: Ideal for NAS systems in bedrooms, home offices, recording studios, and other noise-sensitive environments.
- No fan-related dust buildup: Dust accumulation on fan blades and cooling fins can gradually reduce cooling performance.
- No fan bearing wear: Without a cooling fan, there's one less mechanical component that can wear out.
The metal bracket and heatsink also help dissipate heat. The design goal is simple: sufficient cooling without unnecessary noise.
4. Real-World Testing: 15 Hours of Continuous Traffic
A peak throughput figure of 9.4Gbps means little if it cannot be sustained.
That's why we ran a 15-hour continuous iperf3 traffic test.
The multi-threaded test maintained a stable 9.47–9.49 Gbit/s, with zero interruptions recorded at the end of the test.
The theoretical line rate of 10GbE is 10 Gbit/s. After accounting for Ethernet frame overhead, the preamble, and inter-frame gaps, practical TCP throughput in this type of test typically reaches approximately 9.4–9.5 Gbit/s.
In other words, the MR27F12 isn't merely approaching 10GbE performance. It runs close to the practical throughput ceiling and sustains that performance over an extended period.
For NAS systems, backups, and media libraries where large amounts of data need to move continuously, 15 hours of stable throughput with zero recorded interruptions is more meaningful than a short peak benchmark.
5. One M.2 Slot, One Flexible Cable
The MR27F12 uses a three-part design: a main card, a daughterboard, and a flexible cable.
- Main card: 22 × 80 mm, installed in a compatible motherboard M.2 slot and powered directly through the slot. No external power supply is required.
- Daughterboard: 31 × 54 mm, installed at the chassis bracket position, with an externally accessible SFP+ port.
- Flexible cable: 20 cm long, with a 13-pin connector at each end.
Why use a flexible cable?
Because cable routing is often one of the biggest challenges in compact systems.
In ITX cases, NAS enclosures, and industrial PCs, the M.2 slot and rear chassis bracket may be on different planes. Graphics cards, drive cages, and CPU coolers can further restrict the available space.
A rigid adapter may interfere with a graphics card or prevent the side panel from closing. A flexible cable offers more freedom to route the connection around these obstacles.
The main card stays in the M.2 slot while the flexible cable brings the SFP+ port to the rear of the chassis, without requiring a separate PCIe expansion slot.
The adapter uses PCIe 3.0 x2, with a signaling rate of 8.0 GT/s per lane. Its theoretical one-way bandwidth is approximately 15.75 Gbit/s, sufficient for a single 10GbE connection.
At just 53g net weight, the adapter also places minimal physical load on the motherboard.
6. Systems and Features: What Does It Support?
7. Four Things to Check Before Buying
1. M.2 Slot & Chassis Bracket
The main card requires an M.2 2280 slot. It is compatible with B+M Key slots and can also be used in compatible M Key slots, operating over PCIe x2. Before installation, check that the daughterboard fits your chassis bracket opening.
2. The adapter supports 10G and 1G, not 2.5G or 5G.
If your switch supports only 2.5G or 5G, the MR27F12 cannot negotiate those intermediate speeds and will fall back to 1G. For mixed-speed copper Ethernet environments, consider a 10GBASE-T solution instead.
3. The optical transceiver is sold separately.
The SFP+ module is not included. You'll need a compatible 10G SR multimode or LR single-mode transceiver, along with the appropriate fiber-optic cable. Make sure the transceiver matches your network equipment and fiber type.
4. Check macOS driver requirements and the chassis bracket opening.
The RTL8127 is now officially supported on macOS. For the best compatibility, make sure your Mac is running a supported macOS version.
Also, check the available chassis bracket opening and internal clearance before installation. The SFP+ daughterboard must fit the intended mounting position, and the 20 cm flexible cable needs sufficient room for routing without being pinched or excessively bent.
Final Thoughts
10GbE doesn't necessarily need a cooling fan. It doesn't necessarily need a dedicated PCIe slot, either. And it doesn't necessarily need an external power supply.
1.79W. Fanless. 53g. One M.2 slot and one flexible cable.
The LEKUO MR27F12 brings 10GbE connectivity down to a form factor that takes up barely any space. It won't be the centerpiece of your system, but it will quietly keep delivering the 9.4 Gbps throughput it's designed to achieve.
LEKUO — Network • Storage • Serial Expansion Solutions
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