Firewall Mini PC N355 (Upgraded N305) - 6 x 2.5GbE Fanless Firewall

In this review the Firewall Mini PC N355 is evaluated as a compact, fanless appliance aimed at home labs, small offices and network enthusiasts who need multiple high-speed LAN ports and flexible OS support. The bottom line is that this micro appliance delivers unusually strong I/O for its size: with six native 2.5GbE ports, DDR5 memory support and dual M.2 NVMe slots, it is primarily for users who want a dedicated hardware platform for OPNsense, OpenWrt, ESXi or Windows 11 Pro without the bulk of a rack chassis.

Key Features

• 12th Gen N355 processor: The Twin Lake N355 with 8 cores and up to 3.9 GHz offers enough singlethread and multicore performance for firewall, routing and light virtualized services without high power draw.
• Six 2.5GbE LAN ports: Native i226V 2.5GbE interfaces provide multiWAN or LAN segmentation at 2.5x the speed of gigabit, useful for modern ISP speeds and internal backplane traffic.
• DDR5 and NVMe storage: Single DDR5 SODIMM slot at 4800 MHz and two M.2 NVMe slots let users allocate fast storage for OS, logs and caching to keep throughput high under load.
• Fanless with optional fan support: Passive cooling keeps the unit quiet in normal use, with a 12V 4pin fan option included for higher ambient or sustained load environments.
• Triple display and rich I/O: Dual HDMI/DisplayPort plus TypeC support 4K@60Hz, while USB3.2, USB2.0, SATA3 and TF card slot give flexible connectivity for local management and storage.
• MultiOS compatibility: Ships with Windows 11 Pro preinstalled but supports OPNsense, Linux, ESXi and OpenWrt for those who prefer a dedicated firewall OS.

Who It's For

The Firewall Mini PC N355 is best for small business IT administrators, home lab enthusiasts and network professionals who need multiple highspeed physical interfaces and the ability to run a dedicated firewall or virtualization host in a compact, lownoise package. Its combination of 2.5GbE ports and NVMe slots makes it ideal where throughput and storage speed matter.

It is less suited to users who need extremely high CPU horsepower for heavy virtualization of many VMs or heavy DPI throughput beyond the N355 class, or those who require a fully rackmount chassis with hotswap enterprise features. Consumers who only need a simple home router with WiFi should look elsewhere for simpler turnkey devices.

Pros & Cons

Pros

• Six native 2.5GbE ports let you build multiWAN or multiLAN topologies without additional adapters.
• DDR5 RAM and two NVMe slots provide modern, fast memory and storage options for caches and OS images.
• Fanless design keeps noise to a minimum while still offering an optional 4pin fan for added cooling.
• Wide OS support including OPNsense, Linux and ESXi for flexibility in deployment.

Cons

• The N355 is efficient but not a highend datacenter CPU - very heavy DPI or many simultaneous VMs may push it beyond optimal performance.
• Small form factor limits internal expandability compared with larger rack units.

Specifications

Processor	12th Gen Twin Lake N355, 8 cores 8 threads, up to 3.9 GHz
LAN	6 x Intel i226V 2.5GbE ports
Memory	1 x DDR5 SODIMM slot, 4800 MHz
Storage	2 x M.2 2280 NVMe PCIe 3.0 slots, 1 x SATA 3.0 for 2.5" SSD/HDD
Graphics / Display	Integrated UHD Graphics, 2 x HD + TypeC triple display support 4K@60Hz
Cooling	Fanless design; 12V 4pin fan support (cable included)
OS Support	Windows 11 Pro preinstalled; supports OPNsense, Linux, ESXi, OpenWrt

Our Verdict

For users who need concentrated Ethernet density and modern storage in a quiet micro appliance, the Firewall Mini PC N355 is an excellent value. It strikes a practical balance between performance, I/O and power efficiency, making it a solid choice for small offices and home labs that will run OPNsense or a lightweight hypervisor. Buyers wanting large scale virtualization or enterprise features should consider larger hardware.

Frequently Asked Questions

Can this run OPNsense reliably?
Yes. The unit supports OPNsense and offers native 2.5GbE ports and NVMe storage that are well suited to a dedicated firewall installation.

Is the unit noisy during use?
It is designed as fanless and is quiet in normal operation; a 12V 4pin fan can be installed if additional cooling is needed under sustained heavy load.

How many drives can I install?
Internally you can use two M.2 NVMe drives plus one 2.5" SATA drive via the included SATA 3.0 cable.