Firewall: hardware requirements guide
Stateful packet filtering, IDS/IPS (pfSense/OPNsense).
Needs no bulk storage — a small boot SSD is enough. Spend the budget on CPU, RAM and network instead.
Hardware requirements by tier
Three tiers for every workload: the minimum that works, the recommended sweet spot, and the comfortable headroom level. These are the same tiers the WisePC decision engine uses when it plans a build around your goal.
| Tier | CPU cores | RAM | Storage | GPU | VRAM | Network |
|---|---|---|---|---|---|---|
| Minimum | 2 cores | 2 GB | 0 TB (ssd) | None | — | 1 GbE |
| Recommended | 4 cores | 4 GB | 0 TB (ssd) | None | — | 2.5 GbE |
| Comfortable | 6 cores | 8 GB | 0 TB (ssd) | None | — | 10 GbE |
| Overkill | 10 cores | 13 GB | 0 TB (ssd) | None | — | 10 GbE |
Beyond Comfortable — 10 cores, 13 GB RAM, 0 TB (SSD): headroom you will never use for this workload alone. Put the difference into storage, backup or silence.
Recommended system shape
Derived by the decision engine from the recommended tier — the same logic that plans full builds.
- Form factor
- sff
- Build style
- prebuilt
- Drive plan
- Needs no bulk storage — a small boot SSD is enough. Spend the budget on CPU, RAM and network instead.
Light requirements (4 threads, 4GB RAM) fit a sff prebuilt system — simpler and more efficient than building from parts.
One box or a separate machine?
Whether this workload deserves its own system or should live on the main server.
Keep on the main server
Lightweight always-on service — a separate system would add cost, energy and maintenance for no benefit.
What will it cost?
Market-neutral EUR bands from the reference drive model (≈ = estimated street price). Live component prices resolve on the build page for your region.
- Array energy / year
- ≈ €33/yr (∼15 W idle)
Compute (CPU, board, RAM, GPU) is not included — see the recommended build for live prices.
Also covered in this guide
Router / gateway
Routing, NAT, DNS for the home or lab network.
VPN
WireGuard/OpenVPN endpoint for secure remote access.
VLANs
Segmented network with VLAN-aware switching.
2.5GbE network
2.5 gigabit connectivity, great for fast network storage and backups.
Which tier do you need?
- Pick Minimum (2 cores, 2 GB RAM) only for a single-purpose machine on a tight budget — expect little headroom.
- Recommended (4 cores, 4 GB RAM) is the sweet spot: enough for the workload plus the usual side-services, without overspending.
- Pick Comfortable (6 cores, 8 GB RAM) when this workload shares the machine with others or will grow — you pay for headroom, not for anxiety.
- GPU rule for this workload: None.GPU rule for this workload: None (no discrete VRAM needed).
Frequently asked questions
How much RAM does firewall need?
2 GB is the sensible minimum, 4 GB covers most real setups, and 8 GB gives comfortable headroom for growth and extra services.
How many CPU cores does firewall need?
A 2-core CPU is the minimum, 4 cores is the recommended sweet spot, and 6 cores is comfortable when it shares the machine with other workloads.
Does firewall need a dedicated GPU?
No — integrated graphics or a headless setup is enough.
What storage and network does firewall expect?
Storage: 0 TB of SSD is the recommended baseline (0 TB minimum, 0 TB comfortable). Network: 2.5 GbE is the recommended baseline.
What runs well alongside firewall?
It pairs naturally with: Router / gateway, VPN.
How much power does firewall use?
The storage array idles around 15 W (≈ 33 €/year at 0.25 €/kWh). The full system adds CPU, board and fans on top — see the cost section for the honest bands.