The Cheapest 10GbE - Two Cards, One Cable, No Switch

Cheapest SFP+ card we hold, twice, plus the cheapest 10G direct-attach cable. Pick the cable length from the table below to match your actual run - the shortest is rarely the right one.

SFP+ cards for this build

Any two of these will talk to each other. A badged row is a third-party board asserting the named chipset rather than the maker's own card.

Pick your cable length

Passive direct-attach copper, by length. A DAC is a fixed-length cable with the transceivers moulded on - you buy the whole run at once rather than a cable plus two modules.

Why this build exists

Almost every guide to getting 10GbE at home starts by pricing a switch, and for most people that is the wrong place to start. The common case is not a network that needs upgrading. It is two machines that need a fast path between them - a workstation and a NAS, a desktop and a backup server, two nodes of a small cluster - while everything else in the house carries on over the gigabit it already has and is perfectly happy with.

For that case you do not need a switch at all. You need one card in each machine and one cable between them. The two cards form their own two-device network, entirely separate from your existing one, and each machine keeps its normal connection for internet and everything else. Nothing about your router, your existing switch or your other devices changes.

That is what makes this the cheapest real 10GbE that exists, and it is why this page is the one we would point a first-time buyer at. The parts list above is priced live, so the figure you are reading is what the build costs today rather than what it cost when somebody wrote a guide.

What you are buying and why

Two network cards, one per machine. They should be the same interface type as each other - two SFP+ cards or two RJ45 cards - because they connect to each other directly and nothing sits in between to translate. Our parts list picks SFP+, because with a direct-attach cable it is the cheaper and cooler of the two paths, and because the second-hand enterprise supply that makes these cards inexpensive is overwhelmingly SFP+.

One cable. For SFP+ that is a passive direct-attach copper cable, which arrives as a single object with the connector ends permanently attached. Measure the run before ordering, because the length is fixed at purchase and cannot be changed later. Buy a little longer than the straight-line distance; cables go around things.

Two free PCIe slots, one in each machine. This is the requirement people discover too late. These are PCIe cards and they need a slot with enough lanes and enough physical space, which small-form-factor desktops and some consumer NAS units simply do not have. Check before you buy, not after.

That is the entire bill of materials. No switch, no transceivers to match, no optics, no structured cabling.

Setting it up, at the level we are willing to describe

The concept is simple and the same on every platform. The two new cards form a network with no router and no DHCP server on it, so nothing is going to hand them addresses. You give each one a fixed address in a range you are not using anywhere else, with both on the same subnet, and no gateway - because this link does not go anywhere except to the other machine.

Then you point whatever you are doing at that address specifically. Your NAS share is reachable at both its normal address and its new one, and only the new one is on the fast link, so if you connect by hostname you will silently keep using the old path and wonder why nothing changed. This is the single most common way this build disappoints people, and it is a configuration mistake rather than a hardware one.

We are deliberately not writing the steps. Assigning a static address is a different procedure on TrueNAS, on Proxmox, on Unraid, on Synology, on Windows and on each Linux distribution's network manager, those procedures change between versions, and each of those projects maintains its own current documentation. A copy of those steps on this page would be wrong within a year and we would not notice. Find your platform's own network configuration documentation and follow that - it is the same policy we apply to controller firmware, and for the same reason.

What is worth saying is the order: get the link up and confirm each machine can reach the other's new address before changing anything about how your applications connect. If the two addresses cannot see each other, no amount of share reconfiguration will help.

What this build cannot do

It connects exactly two machines. That is not a limitation you can work around with a second cable - a third machine means a switch, and that is a genuinely different purchase with genuinely different considerations.

Used enterprise 10GbE switches are cheap for the same reason the cards are, and they arrive with the characteristics enterprise equipment has: fans sized for a datacentre rather than a study, meaningful idle power draw, and in many cases a management interface that assumes you know the vendor's command line. There is a well-documented enthusiast rabbit hole here and it is worth reading before committing - ServeTheHome's used-switch coverage is where most people end up and is a reasonable place to start. Newer small 10GbE switches aimed at prosumers avoid the noise problem and cost considerably more.

One machine can hold two cards, and people do use that to daisy-chain three machines, with the middle one routing between the two links. It works. It also means the middle machine has to be running for the other two to talk, and you have taken on a routing configuration to save the price of a switch. We would not recommend it as a first build.

Finally, this does nothing for internet speed, and it is worth being explicit because the question comes up. The link between your two machines has no bearing on the connection between your house and the world. This is a local file transfer upgrade.

Before you order

Confirm the PCIe slots exist, in both machines, with physical clearance for a full-height or low-profile card as appropriate. Card brackets are frequently the wrong height for the case and a replacement bracket is not always included.

Confirm your operating systems support the cards. For the models on this site the drivers ship in the mainline Linux kernel, which covers TrueNAS, Proxmox, Unraid and ordinary Linux; Windows support varies by card and age and is worth checking against the maker's current driver page for your specific model.

Measure the cable run and add margin.

Then do the arithmetic that the hub page opens with, because it applies here too: this link tops out around 1,250 MB/s, and it will only ever move data as fast as the slower end can produce it. If the storage on one end is a single mechanical drive, you will not see the difference you paid for, and the honest answer is to spend the money on the array instead.

Where to go next

The 10GbE hub covers the SFP+ versus 10GBASE-T decision and every card, cable and module we track · the RAID planner helps work out whether your array can feed the link you are about to build · NAS devices is usually the machine at the other end.

Frequently asked questions

Sources

Specification claims on this page were checked against the pages below on 4 August 2026. Where a widely-repeated figure did not survive that check, we report what the source says now and say so in the text rather than repeating the familiar number.

1. NVIDIA (Mellanox) - ConnectX-3 EN product line and lifecycle status (nvidia.com, 2026)
   Used for: that ConnectX-3 has reached end-of-life status with NVIDIA, and the MCX311A / MCX312A / MCX314A part-number family. EOL means no new firmware or driver work from the maker; it does not mean the card stops working, and the page says so in those terms.
2. The Linux kernel project - mlx4, mlx5, ixgbe and i40e in-tree Ethernet drivers (kernel.org, 2026)
   Used for: that mlx4 (ConnectX-3), mlx5 (ConnectX-4 and later), ixgbe (Intel 82599/X520, X540, X550) and i40e (X710) ship in the mainline Linux kernel. This is why an end-of-life card can still be a sane purchase, and it is a documented fact rather than a forum claim.
3. DatacenterDisk - Live catalogue - NIC, DAC and transceiver listings (datacenterdisk.com, 2026-08-11)
   Used for: every price on this page, read from our catalogue at request time. Seeded 11 August 2026: 24 network cards across 6 models, 24 DAC cables, 8 transceivers. Every card is split tier 1 (the listing is that part) or tier 2 (a third-party board asserting that silicon).
4. DatacenterDisk - Sourcing note - power figures and compatibility claims (datacenterdisk.com, 2026-08-11)
   Used for: We publish no per-port wattage for either cabling path. The relationship - 10GBASE-T draws more power and runs hotter than SFP+ direct attach - is documented at product level and is stated here. The magnitude is not, because we have not fetched and logged a source we can cite for it. Separately: every 'compatible with' phrase shown on this site is stored as a seller claim at tier 2 and badged wherever it renders. We have not tested any module against any switch.