Firewall Mini PC N355 (Upgraded N305) - Fanless 4 x 2.5GbE Security

In this review of the Firewall Mini PC N355 (Upgraded N305) the bottom line is simple: this is a compact, fanless security appliance built for small offices, home labs, and edge deployments that need multi-gigabit wired throughput and flexible OS support. The N355 dual-core family design and DDR5 memory options deliver noticeably better packet handling than typical gigabit boxes, and the four Intel i226V 2.5GbE ports make it well suited for routing, firewalling and lightweight virtualization. For anyone evaluating an OPNsense or Linux-based hardware firewall, the combination of AES-NI capable CPU, NVMe storage and quiet operation is the single biggest reason to consider it.

Key Features

• Processor: The 12th Gen N355 Twin Lake processor provides 8 cores and burst clocks up to 3.9 GHz for responsive packet processing and encrypted VPN workloads.
• Multi-Gigabit Networking: Four Intel i226V 2.5GbE ports deliver up to 2.5x the throughput of gigabit Ethernet for faster inter-VLAN and WAN/LAN traffic handling.
• Memory and Storage: DDR5 SO-DIMM support and two M.2 NVMe slots plus two SATA3 ports allow ample memory and fast system/storage configurations for caching and logging.
• Quiet Fanless Design: The passive chassis runs with minimal noise and the included 4-pin fan cable allows adding a small fan if higher-duty cooling is required.
• Display and I/O: Integrated UHD graphics with 4 display outputs including Type-C and DP support easy console access and troubleshooting when installing software such as OPNsense or ESXi.
• Flexible OS Support: Officially supports OPNsense, Linux, ESXi and OpenWrt, enabling a range of firewall, routing and virtualization use cases.

Who It's For

The Firewall Mini PC N355 is ideal for small business IT administrators, home lab enthusiasts, and network integrators who need a compact, low-power appliance with multi-gigabit wired ports and support for open firewall OS options. It works well where AES-NI acceleration, NVMe boot, and multiple Sata/NVMe drives are useful for logging, caching or running small virtual machines.

Those who want a plug-and-play consumer router with built-in Wi-Fi or who require extremely high-end firewall throughput for large enterprise cores should look elsewhere; this unit targets edge deployments and modest throughput scenarios rather than carrier-class aggregation.

Pros & Cons

Pros

• Compact, fanless chassis that keeps noise to a minimum while providing multiple 2.5GbE ports.
• Solid hardware feature set for a micro appliance: DDR5 support, AES-NI capable CPU and dual NVMe slots for fast storage.
• Wide OS compatibility including OPNsense and ESXi for flexible firewall and virtualization setups.
• Rich I/O including Type-C, DisplayPort and two HDMI outputs for management and console access.

Cons

• Not intended as a wireless gateway since there is no integrated Wi-Fi; external APs are required.
• Although fanless by default, heavy sustained loads may benefit from the optional small 12V fan accessory.

Specifications

Processor	12th Gen N355 Twin Lake, up to 3.9 GHz, 8 cores/8 threads
Network Ports	4 x Intel i226V 2.5GbE LAN ports
Memory	1 x DDR5 SO-DIMM 4800MHz, up to 48GB
Storage	2 x M.2 2280 NVMe PCIe 3.0 slots and 2 x SATA 3.0 for 2.5" drives (SATA cable included)
Graphics & Displays	Integrated UHD Graphics (32 EUs) with 2 x HDMI, 1 x DP, 1 x Type-C; supports 4K@60Hz
Power & Cooling	Fanless design, supports 12V 4-pin small fan (cable included); power adapter included

Our Verdict

The Firewall Mini PC N355 is a strong value for small networks and home labs that need multi-gigabit wired performance, flexible OS choices and quiet operation. It pairs modern DDR5 memory and NVMe storage with AES-NI capable silicon, making it a practical hardware platform for OPNsense, Linux routers or light virtualization without excessive cost or footprint.

Frequently Asked Questions

Can I run OPNsense or ESXi on this device?
Yes, the appliance supports OPNsense, Linux and ESXi, and the vendor notes BIOS access via the Delete key for configuration.

How many drives can I install?
There are two M.2 NVMe slots plus two SATA 3.0 ports for 2.5" SSD or HDD, and a SATA cable is included.

Is the unit noisy under load?
It is fanless by default for quiet operation; a small 12V 4-pin fan may be added if needed for sustained high-load cooling.