Most PC builders never use more than one PCIe slot in the entire lifecycle of their system. Besides the primary x16 slot, all the other PCIe slots on most motherboards remain vacant for years. You may think the smallest of them, the PCIe x1 slot, is next to worthless, but it's one of the most powerful upgrade routes on your motherboard. Whether your rig is a bit dated or you want to enhance your motherboard's feature set anyway, the humble PCIe x1 slot is capable of much more than you think. You could upgrade to 5GbE or 10GbE LAN without changing your motherboard, add extra USB or SATA ports instead of buying a subpar hub, and add Wi-Fi 6E or 7 capability to your motherboard if you wish. Despite having access to a single lane, a PCIe 3.0 x1 (8 Gbps) or PCIe 4.0 x1 (16 Gbps) slot is more than sufficient for many useful upgrades, and can transform your PC experience more than most upgrades that you usually consider.

Add more ports via PCIe instead of wasting money on a hub

Forget about removing devices anymore

Every PC user eventually runs out of their stock I/O stack, especially those using budget or older motherboards. Manufacturers try to cut costs wherever possible, and I/O is one of the first areas they trim. This usually translates into users running out of USB ports on the motherboard. Unless you bought a mid-range or high-end board, you probably already have more USB 2.0 than USB 3.0 ports, let alone USB 3.2 Gen 2 or something even faster. On top of that, once you have accumulated enough devices over time, you're forced to make tough choices when you need a vacant USB port without resorting to your PC's front I/O. Even the bare minimum, i.e., a keyboard, mouse, headset, speaker system, external hard drive, and a few wireless dongles, can saturate the number of USB ports on most motherboards.

You could buy a USB hub like most people do. It seems convenient, and gives you extra USB ports that solve the problem. However, USB hubs are severely limited in terms of bandwidth. They essentially split the bandwidth of a single USB port on the motherboard to power the onboard ports. A PCIe-to-USB expansion card, on the other hand, is a dedicated line to the system using the high-speed PCIe bus. It features its own USB controller and enough bandwidth to adequately power high-speed USB devices. You're not only getting extra ports, but also better-quality ports, solving your problem effectively.

Another way to make use of your vacant PCIe x1 slot is to add a SATA expansion card. If you're a data hoarder or have numerous old hard drives with archival data, you can easily run out of SATA ports on the motherboard. A PCIe-to-SATA card is one of the best ways to add more SATA ports to your PC. You could also add a USB-C power delivery card via PCIe if you wish to have fast charging support on your PC. Your smartphone, laptop, and other USB-C devices can be topped up directly from your PC when you're working or gaming on your setup.

A PCIe Wi-Fi card beats a USB Wi-Fi adapter hands down

Don't settle for mediocrity

Wi-Fi is usually not a priority on a desktop PC, but it has its perks. Maybe your Ethernet connection goes down one day, and you need to connect to a wireless hotspot to meet a deadline. Maybe you switch rooms or apartments and don't have the luxury of Ethernet for a few days. Having a Wi-Fi motherboard can be a lifesaver in such situations. Most modern motherboards have integrated Wi-Fi and Bluetooth, but if your board is old enough, you may not have the feature. Some motherboards also have subpar or outdated Wi-Fi adapters that are as good as useless, so you need something to bridge the gap. Most users default to USB Wi-Fi adapters that are cheap and convenient, but they're usually plagued with poor internals, interference from neighboring ports, and overheating.

A PCIe Wi-Fi adapter will always beat a USB model, thanks to better performance, stability, and cooling efficiency. The PCIe x1 slot (PCIe 3.0 and 4.0) provides more than sufficient bandwidth for Wi-Fi 6E and even Wi-Fi 7 cards. The reduced interference, better shielding, higher-grade antennas, and better cooling together make PCIe Wi-Fi cards the ideal way to get your old PC online. You need to open your case to install a PCIe card, unlike a USB adapter, but the benefits are overwhelmingly worth it.

Get a high-speed NIC instead of buying a whole new motherboard

A godsend for power users

Ethernet is way more important now than it was 5–7 years ago. Earlier, even Gigabit LAN was overkill for most users, but today, more and more users are gravitating toward NAS and home labs. These high-bandwidth systems need multi-gig Ethernet, preferably 5GbE or 10GbE. Most motherboards, even in 2026, don't provide such adapters by default, and if your board is even a few years old, chances are you have a 2.5GbE port at most. This leaves you with three options if you want to make the most of your NAS or home lab: buy a new motherboard, build a separate system, or install a PCIe NIC with 5GbE or 10GbE capabilities.

A PCIe Ethernet card can instantly elevate your existing PC's networking chops, even if your internet plan is sub-Gigabit. The internal data transfer between your NAS or home lab and other devices can benefit immensely from the enhanced throughput of an advanced NIC. You'll no longer be capped by your network adapter's maximum bandwidth, allowing your devices to communicate at a much faster rate. Whether it's automated backups, virtual machines, media streaming, or file transfer, your system will benefit more from a high-speed PCIe than faster storage or more memory.

PCIe is the superior way to expand your PC's capabilities

Thanks to the higher bandwidth, power delivery, and cooling efficiency, PCIe expansion cards beat M.2 variants and virtually any other options. Even the tiny PCIe x1 slot on your motherboard can easily accommodate high-speed NICs, Wi-Fi cards, and USB adapters to bolster your PC's feature set. Most users don't consider it a useful slot, but when you truly feel the lack of a particular port or feature, the PCIe x1 slot comes out on top.