Flat Ethernet cables trade tidier home wiring for reliability risks, Engadget reports

Engadget said flat and round cables rated for the same speed perform nearly identically under perfect conditions, but the differences emerge in real-world use. Standard Ethernet cables consist of multiple wire pairs twisted around one another; the twisting prevents signals in one pair from interfering with the others, which can slow speeds and destabilize connections. Flat cables still use twisted pairs, but those pairs are laid in a line, making them more susceptible to interference from each other. Some round cables also include additional shielding against outside devices, a feature Engadget said is typically not available in flat cables.

The wire gauge inside the cable adds another tradeoff. To keep flat cables thin, manufacturers typically use thinner wire than in round cables. Thinner wire has more electrical resistance, so flat cables can degrade signals over a long enough distance, according to the report.

Engadget said the larger practical problem is how flat cables tend to be used. They are easy to bend around corners, run under doors and hide beneath rugs, but those applications increase the chance of failure. Bending a cable or repeatedly compressing it under a door can damage the wires inside regardless of shape. Flat cables use thinner wires and, because the wires are laid in a row, lack the slight cushioning that the round shape can provide, the report said.

The report did not conclude that flat cables should be avoided in every case. It said they can make sense when a cable must pass under a door or through a space too narrow for a round cable, particularly for renters who cannot make larger changes to their home. Flat cables may also be worth the risk when the alternative is leaving visible wires piled around an office, according to Engadget.

For the fastest and most reliable connection, Engadget said round Ethernet cables are almost always the better choice. The risks of interference and signal degradation from flat cables become significant mainly over considerable lengths, so long runs should use round cables. Over short distances where a cable does not need to be bent into place, flat Ethernet cables can still do the job, the report said.