The short answer

If a device sits in one spot and you depend on it, plug it in. A work laptop that spends the day on video calls, a gaming console, or the TV you watch 4K on all do better on a cable. Anything that moves around the house belongs on Wi-Fi.

Both can be fast. The difference is consistency: an Ethernet cable delivers the same performance at 7 pm as it does at 7 am, while Wi-Fi performance changes with distance, walls, and how many devices are sharing it. Most households end up using both, and the trick is deciding which devices get the cable.

Why a cable and Wi-Fi behave differently

A speed test does not tell the whole story. A phone standing next to the router can post a great number and then drop to a fraction of it two rooms away. A cable does not have that problem, and here is why.

• Wi-Fi is shared airtime. Every device on a Wi-Fi band takes turns; only one can talk at a time. The more phones, TVs, and smart gadgets you have, the longer each one waits for its turn.

• Distance and walls cost speed. As the signal weakens, the router falls back to slower data rates to keep the link alive. Brick, concrete, plaster-and-lath, metal ductwork, mirrors, and large appliances all take a bite.

• Other radios get in the way. Neighbors' networks, microwave ovens, baby monitors, and older cordless phones all share the same airwaves, especially on 2.4 GHz.

• Lost packets get re-sent. When Wi-Fi drops a packet it tries again, which adds delay. That delay changes from moment to moment, and that variation (called jitter) is what makes calls stutter and games lag.

An Ethernet cable is a private, two-way link between one device and your router. Nothing else competes for it, nothing interferes with it, and the delay it adds is well under a millisecond and stays that way. Raw speed is rarely the issue on fiber; steadiness is, and that is what the cable buys you.

Working from home and video calls

Video calls care about a steady upload and low jitter far more than raw speed. A 1080p call uses roughly 2 to 4 Mbps in each direction (approximate), which any RTC fiber plan covers many times over. What the call needs is for that traffic to arrive at an even pace, without gaps.

Wi-Fi hiccups show up as frozen video, robotic audio, and the "your connection is unstable" banner, usually right when someone else in the house starts a stream or a download. On a cable, those symptoms almost always disappear. If you still see them while wired, something else is wrong and we would like to hear about it.

Most modern laptops have no Ethernet port, but that is easy to fix. A USB-C to Ethernet adapter costs about $15 to $30 (approximate), and nearly every docking station already has a port built in. Plug the adapter or dock in and the laptop will prefer the wired connection automatically; you can leave Wi-Fi turned on for when you unplug.

Gaming

Online games send a constant stream of tiny packets, so what matters is ping (round-trip delay) and how steady that ping stays. Bandwidth barely enters into it; a competitive shooter uses less data than a music stream.

A wired connection inside the house adds well under 1 ms and does not change. Wi-Fi adds a few milliseconds on a good day, and every lost packet turns into a retry, which shows up as a lag spike, rubber-banding, or a shot that did not register. Those spikes are random, which is exactly what makes them maddening.

If you play ranked or competitive games, a cable is the single biggest improvement you can make. PlayStation and Xbox consoles have an Ethernet port on the back; gaming PCs almost always do; a Nintendo Switch may need a USB Ethernet adapter depending on the dock. Game downloads of 50 to 100 GB benefit too, since a wired link holds its full speed from start to finish.

Streaming in 4K

A 4K stream needs roughly 15 to 25 Mbps (approximate), so your internet plan is almost never the reason a show buffers. The problem is nearly always the last 30 feet between the router and the TV.

Streaming is the most forgiving of the three uses because video buffers ahead. Wi-Fi with a strong signal handles 4K fine. Buffering starts when the signal is weak or the band is crowded, which tends to happen in the evening when everyone is home and online at once. TVs are also often in the worst spot in the house for Wi-Fi: mounted on an exterior wall, tucked behind a cabinet, or at the far end from the router.

If the TV or streaming box has an Ethernet port, use it. Many smart TVs only have a 100 Mbps port, which is still four times what 4K needs. Apple TV, Roku Ultra, and most other streaming boxes include a port as well.

When Wi-Fi is the right choice

Wi-Fi is the right answer for most of the devices in your home. Phones, tablets, a laptop on the couch, thermostats, doorbells, and smart speakers all need to move or live where no cable can reach, and none of them are sensitive to a few milliseconds of jitter.

It is also the practical answer if you rent, if the room has no reasonable path for a cable, or if your gaming and streaming are casual enough that an occasional hiccup does not bother you.

There is a side benefit to wiring the devices that matter: every TV or console you move to a cable stops competing for airtime, so the Wi-Fi devices that remain get faster and steadier too.

Getting the most out of your Wi-Fi

Router placement makes a bigger difference than any setting. A few changes fix most complaints we hear.

1. Put the router out in the open. Central in the house, up off the floor, and not in a closet, a basement corner, behind the TV, or in the utility room next to the fiber box. Wi-Fi radiates outward from the router, so a router at one end of the house serves only half of it.

2. Use the faster band. 5 GHz (and 6 GHz, if both your router and device support it) is much faster and far less crowded than 2.4 GHz. 2.4 GHz reaches farther through walls, which makes it the right band for smart home gadgets, but not for a TV or laptop.

3. Count the walls. Each wall between you and the router costs speed; exterior walls, brick, and anything with metal in it cost the most. Moving a device one room closer often beats any upgrade.

4. Use mesh, not a range extender. A plug-in extender rebroadcasts everything it hears and cuts throughput roughly in half. A mesh system with multiple units keeps full speed, and one with a wired connection between units is the best Wi-Fi you can have.

5. Keep the router's firmware current. Most routers update themselves; if yours has an app, check that automatic updates are on.

RTC Provides Whole-Home Wifi powered by Calix routers. We highly encourage customers to download our companion RTC Fiber App (buttons below), and check out the Set-Up Guide for additional information on how to get the most out of your RTC Whole-Home Wifi!

Running a cable without rewiring the house

You do not need jacks in every room to get the benefit. A single cable to the right spot covers most of it.

• One long cable is still Ethernet. Cat5e and Cat6 both carry a full gigabit up to 328 feet (100 m), so a cable run along a baseboard or through a basement ceiling loses nothing. Flat cable slips under carpet edges and door frames.

• One cable per room, then a small switch. A 5-port unmanaged switch costs about $15 to $20 (approximate) and lets one run serve the TV, the console, and a PC in the same room.

• Reuse old coax. If the house has cable TV coax in the walls, a pair of MoCA adapters turns it into a gigabit-class wired link that performs like Ethernet. This is the best option in many older homes.

• Powerline adapters are a last resort. They send data over the electrical wiring and are hit or miss; results depend on how the house is wired and are often no better than good Wi-Fi.

• Have it done once. A low-voltage installer or electrician can run in-wall Cat6 to two or three rooms in a day, usually for a reasonable fee. Cabling outlasts every router and TV you will ever own.

Quick guide

Bottom line: a cable is for consistency and Wi-Fi is for convenience. Wire the few devices that sit still and matter, and give the airwaves to everything else.

Still seeing slow speeds or drops after plugging in? Contact RTC support and we will take a look.