Every packet on the average "wireless" home network makes its last hundred meters over radio precisely because pulling cable is inconvenient — not because radio is better. On every axis networking engineers actually measure, a good Ethernet run wins. This page is the case for wiring the handful of devices where the difference is felt daily.
The difference in one word: shared
Wi-Fi is a shared, half-duplex medium: every device in range takes turns talking, listening before it speaks, and re-sending when it detects collisions — the etiquette inherited from ALOHAnet and 802.11 in general. An Ethernet switch gives every port its own dedicated lane and runs full-duplex: send and receive simultaneously, no contention, no waiting for neighbours to finish talking. That single architectural fact causes every downstream difference.
| Property | Wi-Fi (even great Wi-Fi) | Ethernet (cat5e/cat6) |
|---|---|---|
| Real-world speed far from the router | Falls 3–10× through walls | Identical at 100 m — physics doesn't do rooms |
| Latency / jitter | Low average, occasional 50–300 ms spikes when the air gets busy | Sub-millisecond locally, extremely stable; no contention spikes |
| Behaviour when the neighbour upgrades their router | You both slow down (shared spectrum) | Nothing happens |
| Simultaneous streams per device | Half-duplex airtime shared across all clients | Every port full-duplex at its rated speed |
| Throughput vs. distance | Drops continuously with each obstacle | Flat 100% line rate to 100 m, then no link |
| Eavesdrop risk | Radio leaks through windows; needs WPA3 to be safe | Needs physical taps of a buried cable |
| Adding ports / cameras / power | Each new radio client costs airtime | Switches are dirt cheap; PoE runs cameras and access points on the same cable |
The numbers that surprise people
- Cat5e — the cable already inside most walls — does 2.5 Gbps on 100 m runs (2.5GBASE-T/802.3bz). The 2004 cable installer may have pre-installed your next decade of speed.
- 10GBase-T needs cat6a for full 100 m (category spec; cat6 hits 10G to about 55 m).
- Gigabit Ethernet's median local latency is ~0.1 ms; busy Wi-Fi on a crowded channel routinely exceeds 10 ms. For games and video calls the difference is audible, not theoretical.
- Ethernet frame loss over a working cable is essentially zero (bit-error rates near 10⁻¹² or better); Wi-Fi loses double-digit percent of frames when a microwave joins the party.
Wiring vs. mesh: why hops cost
A wireless mesh/repeater adds a radio hop — the extender receives on one channel and re-transmits the same frames on (usually) the same channel, so each hop roughly halves the airtime available behind it and adds latency along the path (see the mesh & extender math). A cable behind each far node — Ethernet, or MoCA over coax — carries traffic that never touches the air, so every mesh point behaves like a wired access point at full rate. MoCA (coax) is genuinely fast — MoCA 2.5 tops ~2.5 Gbps — and is the hero of older homes already wired for TV. Powerline (G.hn) is the fallback where neither exists; it's better than its reputation but is at the mercy of your wiring, phase crossings, and noisy sockets.
Wire these five things first
- Your desk machineThe video-call laptop on a USB dock is a 5-dollar cable away from studio-grade stability.
- Every access point / mesh node you can reachWired backhaul converts a mesh from 'best-effort with a wireless hop' to a professional multi-radio layout that keeps full speed — even cheap old-router-as-AP wins (see the Upgrade guide).
- TV, console, set-top boxThe heaviest sustained bandwidth in the house stops eating into everyone's airtime.
- Cameras and access-point PoE runsOne cable = power and data; cameras then never drop because someone microwaved.
- NAS / backup targetMulti-gigabit transfers stop being a Wi-Fi exercise in patience.
"But I hate cables" — the honest decision order
- 1. Existing in-wall cat5e? Terminate/patch it — free multi-gig.
- 2. Coax in each room and no data cable? MoCA adapters.
- 3. Single-floor, short runs? Flat/paintable cat6a under rugs or along trim — genuinely invisible.
- 4. Renting or masonry everywhere? A mesh kit with a dedicated 6 GHz backhaul is the next best thing — the calculator will size it for you.
- 5. Extension sockets and power strips? Powerline works, but stop expecting Ethernet numbers from it.
Verified sources & further reading
External links below were live-checked in September 2026. They back up the specific claims on this page; open them and judge for yourself.
- IEEE 802.3 Ethernet Working Group — official standard homeieee802.org
- Ethernet standard overview (wiki)en.wikipedia.org
- 2.5/5GBASE-T over legacy cat5e (standard summary)en.wikipedia.org
- Category 6 & cat5e cable specificationsen.wikipedia.org
- Power over Ethernet (IEEE 802.3af/at/bt)en.wikipedia.org
- MoCA Alliance over-coax networkingen.wikipedia.org
- ALOHAnet — the shared-radio ancestor of Wi-Fi etiquettecomputerhistory.org