Why a cable can feel better than Wi-Fi
Wi-Fi shares the air with neighbouring networks, microwave ovens, other devices in your home and anything else that uses the same radio frequencies. A cable does not. Data travels inside the wire, so it is not affected by walls, distance within reasonable limits, or other people’s routers. The result is usually a connection that is more consistent, with fewer sudden slowdowns and less variation in delay.
That consistency matters more than raw speed for some jobs. Video calls are sensitive to short interruptions, and a desktop computer, games console or TV box that never moves has little reason to use radio at all. Moving fixed devices onto a cable also leaves more Wi-Fi capacity for phones and tablets.
What an Ethernet cable is
An Ethernet cable is a bundle of twisted copper wire pairs with a plug at each end. Twisting the pairs helps reduce interference. One end plugs into a port on the router (or a switch, a small box that adds extra ports), and the other into the device. There is nothing to configure in most cases: the device usually detects the connection and starts using it.
Most cables you buy are made for ordinary home use, and the plugs are all the same shape, so you can’t tell the category by looking at the connector. The category is normally printed on the cable jacket.
Cable categories in plain terms
Categories describe what a cable is designed to support. The ones you are likely to see are:
| Category | Typical use |
|---|---|
| Cat5e | Gigabit (1 Gbps) speeds over runs up to 100 metres |
| Cat6 | Gigabit speeds, and 10 Gbps over shorter runs, often cited as around 55 metres |
| Cat6a | 10 Gbps over the full 100 metres |
| Cat7 and Cat8 | Less common in homes; Cat8 is aimed at very short runs in data centres |
For most households, Cat5e or Cat6 is enough. Typical home internet plans are well below 1 Gbps, and a gigabit-capable cable does not limit them. Paying more for a higher category is mostly useful if you plan to run cable inside walls, since it is hard to replace later, or if you have a faster local network for something like moving large files between computers.
The 100-metre figure is the usual maximum length for a single run. In a house, you are unlikely to get anywhere near it.
Practical points when buying and laying cable
- Check that the cable is complete copper. Very cheap cables are sometimes made with thinner or lesser-quality conductors.
- Avoid sharp bends, tight staples and running it right alongside mains wiring for long distances.
- Remember the whole path must support the speed you want. A fast cable plugged into an older port that tops out at 100 Mbps will only run at 100 Mbps.
- Flat cables are handy for crossing under doors, but are no faster than round ones.
If your home internet plan is fast, an old device with a 100 Mbps port may be the weakest link in the chain. Checking the port specifications is a quick way to find out.
When a cable cannot be run
Sometimes you want a wired connection but cannot easily drill or lay cable. That is the situation powerline adapters were designed for.
How powerline adapters work
A powerline kit consists of at least two plug-in adapters. One goes into a wall socket near the router and connects to it with a short Ethernet cable. The other goes into a socket in the room you want to reach and has a port for a device (some also include Wi-Fi). The adapters send data over the home’s existing electrical wiring using signals that sit separately from the mains power.
Adapters are normally paired, either at the factory or by pressing a button on each. Most use encryption, and it is a good idea to confirm this is enabled, since the signal travels along wiring that can sometimes extend beyond your own walls in some buildings.
Limits to expect
Powerline performance varies a lot, and the headline speed on the box is a theoretical maximum. Real results depend on:
- the age and quality of the wiring
- whether both sockets are on the same circuit or consumer unit
- electrical noise from devices such as chargers, dimmers and some appliances
- whether the adapter is plugged directly into the wall, which is generally recommended rather than through a power strip
Sometimes powerline works very well, sometimes it works poorly, and it is hard to predict without trying. If you buy a kit, check the retailer’s return policy. It can be a convenient fix for a distant room or a smart TV that struggles with wireless, but it is generally not as dependable as a proper cable.
Choosing between the options
A simple order of preference works for many homes:
- Run a cable if you can, particularly to devices that stay put.
- Try a mesh Wi-Fi system with a wired connection between units if one router cannot cover the house.
- Use powerline where neither of the above is practical.
Wired connections help most with video resolution and streaming services that need steady throughput, and with large software updates that would otherwise compete with everything else on the Wi-Fi. They do not make your internet plan faster, but they can let you get all of the speed you already pay for.