Firewall Hardware Tiers: Celeron vs N100 vs i5 Mini-PCs

The most over-bought component in a homelab firewall is the CPU. People read “firewall” and imagine they need a powerful machine, then buy an i5 or i7 mini-PC that idles at 2% load forever. The opposite mistake — buying too little — is rarer but more painful, because it shows up only when you enable IDS/IPS and watch throughput collapse.

This guide tiers the three silicon classes you’ll actually be choosing between in 2026 mini-PCs and maps each to the workloads that matter. We’re deliberately avoiding fixed price and benchmark claims that go stale; the goal is to get you into the right tier so you don’t overspend or under-provision.

What a firewall CPU actually does

Routing and NAT for a 1 Gbps link is, by modern standards, almost free — any of these chips idles through it. CPU load on a firewall scales with three things:

1. Per-packet processing — more relevant as link speeds climb past 1G toward 2.5G/10G.
2. VPN encryption — WireGuard and OpenVPN encrypt/decrypt in software; this is largely single-thread-bound (WireGuard especially benefits from strong single-core performance and AES-NI is relevant for OpenVPN/IPsec).
3. Deep packet inspection — Suricata/Snort IDS/IPS and DPI plugins like Zenarmor are the real CPU consumers. This is where weak CPUs fall over.

So the honest sizing question isn’t “how fast is my internet,” it’s “will I run IDS/IPS and a VPN, and at what link speed.”

Tier 1: Older Celeron (e.g. J3160, J4125, J6412)

These low-power Celeron/Pentium SoCs powered the first wave of cheap fanless firewall boxes and are still everywhere on the used market. They are 4-core, low-clock, low-TDP parts.

Good for:

• Plain routing/NAT up to 1 Gbps — comfortably.
• A WireGuard tunnel or two at modest speeds.
• A light Suricata ruleset on a 1G link, with headroom shrinking as you add rules.

Strained by:

• 2.5G+ routing with any inspection.
• Heavy Suricata rulesets — throughput drops noticeably once DPI is doing real work.
• High-throughput VPN (single-thread performance is the bottleneck).

Verdict: Still a legitimate choice for a basic 1G home firewall, especially if you already own the box or find one cheap. The newer J6412 (Elkhart Lake) is the strongest of this group and is what ships in appliances like the Protectli VP2420. If you’re buying new in 2026, though, the N100 generally makes more sense (below).

Tier 2: Intel N100 (and N200 / N305)

The N100 is the Alder Lake-N part that has taken over the budget mini-PC and firewall market. It’s a 4-core (no hyperthreading) chip with substantially better per-core performance than the older Celerons, a low TDP, and modern instruction support. The N200 is a slightly higher-clocked sibling; the N305 adds more cores (8) for people who want headroom.

Good for:

• 1G routing with comfortable headroom for IDS/IPS.
• 2.5G routing — the N100 is a sensible match for the 2.5GbE NICs now common on mini-PCs.
• WireGuard at meaningfully higher throughput than the old Celerons, thanks to stronger single-thread performance.
• A reasonable Suricata ruleset on 1G without choking; usable on 2.5G with tuning.

Strained by:

• Saturating a heavy IDS ruleset at 2.5G+ simultaneously with high VPN load.
• 10G workloads (that’s a different conversation — and different NICs).

Verdict: The N100 is the default recommendation for most new home firewalls in 2026. It hits the price/performance sweet spot, it’s everywhere, and it has enough margin that enabling IDS/IPS doesn’t immediately become a problem. If you’re unsure what to buy and your link is 1G or 2.5G, start here.

A buyer beware: many cheap N100 mini-PCs ship with Realtek NICs, which have flaky FreeBSD driver support. For a pfSense/OPNsense firewall you want Intel NICs (the I225-V/I226-V for 2.5G, I210/I350 for 1G). The chip can be great and the box still be a bad firewall because of the NIC. We say more on this in our Protectli vs Netgate hardware comparison.

Tier 3: i5 / i7-class mini-PCs

Core i5 and i7 mini-PCs (often U-series mobile parts, e.g. the i7-10810U in Protectli’s VP4670, or current-gen i5 boxes) bring 6+ cores, hyperthreading, and strong single-thread performance.

Good for:

• 2.5G and 10G routing with inspection.
• Heavy Suricata/Snort rulesets without throughput collapse.
• High-throughput WireGuard and many simultaneous VPN clients.
• Running additional services on the box (though many people prefer to keep firewalls single-purpose).

Overkill for:

• A 1G connection doing basic routing and a light ruleset. You will not see the difference versus an N100, and you’ll pay more and burn more power.

Verdict: Buy this tier when you have a specific high-throughput need: a multi-gig WAN, a heavy DPI deployment, or many concurrent VPN users. Buying it “to be safe” for a 1G home connection is the classic over-provisioning mistake — the extra cores idle.

Matching tier to workload

Workload	Minimum sensible tier
1G routing/NAT only	Old Celeron (J6412) or N100
1G + light WireGuard	Old Celeron (J6412) or N100
1G + Suricata IDS/IPS	N100
2.5G routing/NAT	N100
2.5G + IDS/IPS	N100 (tuned) or i5
Heavy IDS + high VPN load	i5 / i7
10G routing with inspection	i5 / i7

Things that matter more than the CPU tier

• NIC vendor. Intel over Realtek, every time, for a FreeBSD-based firewall. This is non-negotiable for production reliability.
• RAM. 8 GB is plenty for most setups; 16 GB if you run Suricata with large rulesets, big state tables, or DPI. You rarely need more for a pure firewall.
• Storage. A small, reliable SSD/NVMe. Avoid eMMC for write-heavy logging if you can. Capacity needs are modest.
• Cooling. Fanless is great for silence and reliability, but make sure a fanless box’s thermal design suits sustained load if you’ll run IDS hard.

Bottom line

For the large majority of home and small-office firewalls in 2026, the Intel N100 with Intel NICs is the right buy — enough headroom for IDS/IPS and 2.5G, without the cost and power of an i5. Drop to an older Celeron only if you’re recycling hardware or strictly doing basic 1G routing. Step up to i5/i7 only when you have a concrete multi-gig or heavy-DPI requirement. Size for the workload you’ll actually run, and spend the savings on good NICs rather than spare CPU cores you’ll never use.

Further reading

• Protectli vs Netgate hardware comparison
• Best homelab firewall in 2026
• WireGuard on OPNsense vs pfSense