As someone who got into PC-building just so I could run games at high resolutions without compromising on the graphical fidelity or frame rates, I’d instinctively glance at benchmarks before investing in a new component. Although there’s nothing wrong with this train of thought when I’m sifting through different processors and graphics cards, things are vastly different when it comes to mini PCs and thin clients – and that’s something I realized after going deep into the home lab rabbit hole.

Don’t get me wrong: hardware specifications are pretty important, and I’d always check the processing cores, memory slots, and integrated graphics on a mini PC before pulling out my wallet. But instead of reading multiple benchmarks and performance graphs, I’d rather focus on the I/O ports available on a mini PC.

A second Ethernet port is a godsend for networking projects

It can turn your mini PC into a dedicated firewall

On the surface, an extra Ethernet port may not seem like that big of a deal on an everyday machine. But if you’re even remotely into home lab projects, your dual-Ethernet companion can go from an ordinary cluster node or secondary server to a formidable addition to your setup. For starters, creating a custom router/firewall requires two ports: one that hooks up to your LAN switch and another that connects to the Internet-facing WAN interface (unless you opt for VLAN shenanigans).

You could technically opt for a USB-to-Ethernet adapter, but it can result in random disconnections out of nowhere. Not to mention, certain firewall-centric distros might not even recognize your USB adapter when you try installing them. Since you don’t have to combine a built-in RJ45 socket with a makeshift USB adapter, mini PCs with full-fledged dual Ethernet ports aren’t afflicted by these problems.

Alternatively, if you’re using your mini PC as a typical server node (and yes, modern processors can hold their own against virtual guests), two Ethernet connections help you split bridges and VLANs between your containers and virtual machines. While it won’t increase the transfer speeds for individual devices, you can configure Link Aggregation Control Protocol for your tiny home server and enjoy automatic load-balancing, high throughput, and better failover provisions. Heck, for folks who love iSCSI as much as I do, the extra Ethernet port can separate typical LAN devices from the block share traffic on your mini PC.

Extra storage slots make it viable for hardcore storage tasks

That single M.2 SSD slot isn’t good for housing backups

While we’re on the subject of storage protocols, budget-friendly mini PCs, NUCs, and thin clients tend to be limited when it comes to drive bays. The tiniest systems typically include a single M.2 SSD slot, which may be fine for general-purpose setup, but it's less than ideal for tinkerers. After all, storage expansion options are pretty important when you’re deploying server projects, and you could easily end up with overprovisioned storage pools once you start experimenting with virtual guests en masse. Heck, if you’re planning to deploy a high-availability cluster with your mini PCs, you’ll need a spare storage drive to configure ZFS replication/Ceph distributed pools.

The extra storage slots can also come in a clutch when you’re planning to use your tiny companion as a secondary backup rig. Thanks to their (comparatively) inexpensive price tags, efficient power consumption, and small footprint, mini PCs double as incredible remote NAS rigs in 3-2-1 backup environments. Since SSDs are terrible for long-term data retention, you’ll want to add hard drives into the mix, preferably 2.5-inch SATA HDDs that stay firmly lodged inside the miniature chassis.

An OCuLink interface lets you harness external PCIe cards

Or, you can build a Frankenstein’s setup with a spare NVMe M-key slot

Back when Thunderbolt 3 started making the rounds, the idea of a USB slot possessing enough bandwidth to leverage full-fledged GPUs was enough to blow my mind. Sadly, what we ended up with were overpriced eGPU enclosures that weren’t worth the monetary investment. Luckily, OCuLink not only manages to avoid the pitfalls afflicting Thunderbolt setups thanks to cheap docking boards, but it even delivers superior bandwidth compared to the latest versions of its rival standard.

Certain mid-range mini PCs tend to ship with dedicated OCuLink connectors, and although you have to shell out extra money on a power supply for your GPU, this standard is perfect when you want to reuse an old graphics card to add some extra oomph to your server. The best part? Even if your miniature system doesn’t include an OCuLink port, as long as it has a spare NVMe M-key socket, you can use an adapter to add a full-fledged GPU to your setup. And I don’t mean using it just for games, either. I’ve recently paired a multitude of self-hosted services with an LXC running Ollama modules, and these LLMs can add essential quality-of-life features to my app arsenal.

With the right ports, your mini PC can be the most versatile part of your home lab

As much as I adore server-rated hardware, I’ve slowly warmed up to mini PCs over the last two years. Although they won’t possess as many cores, PCIe slots, or memory sockets as my Xeon rig, their versatile nature makes them extremely handy for home server tasks. If you’ve got a decent mid-range system with extra Ethernet ports, decent RAM, and adequate storage, you can turn it into a solid Proxmox hub that’s as great at running containerized services as it is at protecting the rest of your setup with a hardened OPNsense virtual machine. Throw in an external GPU, and it can even run LLMs to aid your FOSS productivity apps in the background.