OPNsense vs pfSense on an N100: Throughput, IPS and Power
Compare OPNsense vs pfSense on an N100 by NIC support, throughput limits, IPS memory needs and power settings, using official hardware documentation.
OPNsense vs pfSense on an N100 is a question of what a particular board can sustain with the intended features enabled. The N100’s four cores, Ethernet controllers, memory and cooling constrain either installation. Published specifications do not establish equal 2.5GbE throughput or a power winner between the two systems.
This comparison focuses on those hardware constraints. For licensing, release schedules and general package differences, use the OPNsense vs pfSense platform comparison. If the appliance has not been selected yet, start with the Intel N100 firewall build guide.
N100 hardware: hold the board constant
Intel’s N100 specifications list four cores and four threads, a 3.4 GHz maximum turbo frequency, one memory channel and a 6 W processor power specification. These describe the processor; they do not certify a firewall workload or a complete appliance’s consumption.
A useful comparison starts with one board and a written configuration record:
| N100 build detail | Keep the same on both installations | Why record it? |
|---|---|---|
| Ethernet | Controller model, cable and negotiated speed | A link limited to 1 Gbps cannot demonstrate 2.5GbE routing |
| Memory and SSD | Installed capacity and storage device | Extra reporting services change the resource budget |
| Firmware | BIOS version and power settings | Different settings make OS attribution uncertain |
| Traffic | Same endpoints, packet mix and direction | A single bulk transfer represents one workload |
| Inspection | Same interfaces, rules and logging policy | Different rulesets compare different work |
These are comparison controls, not benchmark results. Record the exact software versions too; sharing a driver family does not imply that two releases contain identical driver code.
N100 throughput: a 2.5GbE port is only the link rate
Netgate’s sizing guide warns that throughput estimates for third-party hardware are imprecise. Its example of 500,000 packets per second corresponds to 244 Mbps at 64-byte frames and 5.59 Gbps at 1500-byte frames. That is a general illustration of packet-size effects, not a published N100 result.
The practical implication is to compare routing with routing before introducing inspection or encryption. Record the traffic mix, CPU use and negotiated link speed together. A good bulk-transfer result does not establish the same ceiling for small packets, multiple services or inline IPS.
Do not select a distribution solely because an appliance listing says it supports 2.5GbE. Ask for a reproducible result on the intended configuration when that throughput is a purchase requirement. Neither project’s general hardware documentation promises it for every N100 board.
I225 and I226 NIC support on the N100
The FreeBSD igc manual lists I225 and I226 controllers, including I226-V and I226-LM. It documents 2.5GbE operation and features such as checksum offload and receive-side scaling. Check the actual controller and loaded driver on each installation rather than inferring them from the N100 CPU label.
Driver support also does not prove link stability on a particular board. A disconnect or speed change should be investigated before comparing throughput. The I226-V and I225-V differences explain the controller distinction; the i226-V link-drop checklist covers an unstable port.
Inline IPS: spend the N100’s CPU and RAM deliberately
OPNsense’s IPS documentation describes Suricata inspection and its netmap mode. For that mode, check the selected physical interface and driver support. Its interface settings documentation also explains why checksum and segmentation offloading should remain disabled for IPS. A NIC advertising an offload feature is not a reason to enable it in this configuration.
Netgate’s sizing guidance identifies Snort and Suricata as resource-intensive packages. It budgets at least 1 GB of RAM for the inspection package, with some configurations needing 2 GB or more, in addition to the operating system and other services. OPNsense’s recommended hardware tier specifies 8 GB RAM and a 120 GB SSD.
For an N100, the resulting buying advice is to reserve capacity for the actual ruleset and reporting workload. More RAM can address memory pressure; it does not add packet-processing cores. Compare throughput and resource use with inspection disabled and enabled, keeping the rules and interfaces consistent. The N100 vs N305 vs N5105 comparison provides the processor specifications when considering a different board.
VPN throughput: check the cipher and acceleration
Intel lists AES-NI support on the N100. Netgate’s cryptographic-accelerator documentation explains how AES acceleration applies to supported ciphers, including AES-GCM. It is not a blanket throughput promise for every VPN protocol.
Record the tunnel type, cipher, peer hardware and enabled acceleration before attributing a result to OPNsense or pfSense. Keep VPN traffic separate from the initial routing comparison, then evaluate the combined workload that the appliance will actually carry. CPU specifications alone do not establish a winning tunnel speed.
N100 power: compare settings before choosing an OS
The processor’s 6 W specification is not the power draw of the whole firewall. The board, NICs, SSD and power supply are also part of a wall-meter reading. There is no matched OPNsense-versus-pfSense power result in the sources cited here.
Both projects document power controls: OPNsense under System settings and Power Savings, and pfSense under Advanced Miscellaneous settings. Their effect depends on supported hardware and firmware. Record the selected power mode on both installations, along with connected ports and enabled services, before comparing idle and sustained-load readings.
Keep the detailed wattage discussion in N100 idle and load power draw. It provides the separate power context without treating figures from different appliances as an OS comparison.
Choosing OPNsense or pfSense for this N100 build
Choose the software that supports the required configuration on the exact board, then validate routing, inspection and VPN workloads separately. If the existing platform meets those needs, these specifications alone give no reason to reinstall for a promised speed or power advantage.
Before committing to hardware, use the N100 throughput and power calculator to explore its estimated workload envelope. Treat the output as planning guidance and validate the finished appliance. For the installation sequence, continue to N100 OPNsense installation and first boot.
Sources
- Intel Processor N100 Specifications (Intel ARK)
- Hardware sizing & setup (OPNsense documentation)
- Hardware Sizing Guidance (pfSense Documentation, Netgate)
- igc(4) Intel I225/I226 Ethernet Driver (FreeBSD Manual Pages)
- Intrusion Prevention System (OPNsense documentation)
- Interface settings and hardware offloading (OPNsense documentation)
- Cryptographic Accelerators (pfSense Documentation, Netgate)
- Settings and Power Savings (OPNsense documentation)
- Miscellaneous and Power Savings (pfSense Documentation, Netgate)
Related
N100 vs N305 vs N5105: Firewall CPU Comparison
Intel N100, Core i3-N305 and Celeron N5105 compared for OPNsense and pfSense: cores, cache, PCIe lanes, memory channels, power, and who each one suits.
N100 Firewall Setup: OPNsense Install and First Boot
Installing OPNsense on an Intel N100 mini PC: image choice, BIOS prep, ZFS versus UFS, interface assignment, and the first-boot settings that matter.
i226-V Link Drops: Fix 2.5GbE Flapping on OPNsense
Why Intel i226-V ports drop link on OPNsense and pfSense, and an ordered fix list: cabling, forced speed, ASPM, EEE, flow control and driver tunables.