Firewall Mini PC N355 16GB DDR5 128GB SSD - Fanless 6x2.5GbE

In this review the Firewall Mini PC N355 is evaluated as a compact, fanless network appliance aimed at small offices and advanced home labs that need multi-port routing and strong throughput. The bottom line: it stands out for its six native 2.5GbE ports and upgradeable storage and memory, making it a practical choice for anyone who wants a ready-to-run hardware platform for OPNsense or Windows 11 Pro. The review focuses on real-world fit, showing where the unit excels and where users should manage expectations.

Key Features

• 6 x 2.5GbE LAN: Six Intel i226V ports provide higher-than-gigabit throughput for multi-WAN, VLAN and firewall scenarios without extra NICs.
• 12th Gen N355 Processor: Twin Lake N355 with 8 cores and burst up to 3.9 GHz offers adequate CPU headroom for firewall, VPN and IDS/IPS workloads.
• DDR5 16GB RAM: A single DDR5 SO-DIMM slot at 4800MHz supports responsive packet handling and virtualized network services.
• Dual NVMe + SATA storage: Two M.2 NVMe slots plus a SATA 3.0 bay let users configure fast system drives and larger data storage or failover.
• Fanless design with optional fan: Passive cooling keeps noise to zero in typical duty cycles while a 12V 4-pin fan can be added for heavier loads.
• Triple display support: Two HDMI/DP outputs plus a USB Type-C support 4K@60Hz for local management or monitoring screens.

Who It's For

The Firewall Mini PC N355 is aimed at small businesses, network enthusiasts and lab users who need multiple physical 2.5GbE ports in a compact, low-power appliance. It is particularly useful for those running OPNsense, OpenWrt, ESXi or Linux, or who want Windows 11 Pro available for mixed workloads.

It is not for users who require many drive bays, extremely high-end CPU performance, or a plug-and-play consumer router with guided setup. Buyers who need carrier-grade redundancy or dozens of SFP ports should look at rack appliances instead.

Pros & Cons

Pros

• High port density with six native 2.5GbE interfaces makes network design simpler without PCIe add-ons.
• Upgradeable storage and memory with two NVMe slots and DDR5 support allow flexible system configuration.
• Fanless chassis keeps noise out of the room while offering optional active cooling for heavy use.

Cons

• Single SO-DIMM limits maximum RAM capacity compared with dual-channel designs, which may affect memory-heavy virtualized setups.
• Compact chassis offers limited internal drive expansion beyond the single 2.5" bay and two M.2 slots.

Specifications

Processor	Twin Lake Intel N355, 8 cores / 8 threads, up to 3.9 GHz
Network	6 x Intel i226V 2.5GbE LAN ports
Memory	1 x DDR5 SO-DIMM slot, 4800MHz (16GB installed)
Storage	2 x M.2 2280 NVMe PCIe3.0 slots; 1 x SATA 3.0 bay (2.5" SSD/HDD)
Graphics / Display	Integrated UHD Graphics (32 EUs) with dual HD outputs + Type-C, 4K@60Hz support
Cooling	Fanless chassis; 12V 4-pin small fan supported (cable included)
OS Compatibility	Preinstalled Windows 11 Pro; supports OPNsense, Linux, ESXi, OpenWrt

Our Verdict

The Firewall Mini PC N355 is a strong value for small businesses and power users who need multiple 2.5GbE ports and flexible storage in a silent, compact package. It pairs good CPU performance with modern DDR5 memory and dual NVMe capability, making it a capable hardware platform for OPNsense or mixed OS deployments; choose it when port density and low-noise operation matter more than maximum RAM or large internal storage bays.

Frequently Asked Questions

Can this run OPNsense out of the box?
Yes, the device supports OPNsense and similar firewall OS options; Windows 11 Pro is preinstalled if needed.

How many drives can be installed?
It has two M.2 NVMe slots plus one SATA 3.0 bay for a single 2.5" SSD or HDD.

Is active cooling required?
No, the chassis is fanless for quiet operation but includes a 4-pin fan cable if additional cooling is desired under heavy load.