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The copper rate whose cabling grade and heat are both part of the decision

10GBASE-T and the two figures beside it

Ten gigabits over ordinary-looking copper is the rate that made the cabling grade matter to people who had never thought about one. It is also the rate where the power a port draws and the heat it makes stop being a footnote on the data sheet.

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What the standard defines

10GBASE-T carries ten gigabits per second over four pairs of balanced copper, terminated in the same eight-position modular connector as every rate below it. It was published as IEEE 802.3an and has since been folded into the base 802.3 standard.

Its defining figure is reach against cabling grade. Over a Category 6A or Class EA channel, it is specified to the full hundred metres. Over an installed Category 6 channel, the case is covered by separate published guidance rather than by the physical layer itself, the reach is well short of a hundred metres, and the limiting factor is alien crosstalk — the coupling between one cable and its neighbours in a bundle, which Category 6 does not specify and Category 6A does.

The other defining property is effort. Getting ten gigabits down twisted pair takes a great deal of signal processing at both ends, and that shows up as power drawn and heat produced per port, and as a slightly higher latency through the transceiver than the shorter-reach optical and direct-attach alternatives.

What it does not promise

It does not promise a ten-fold transfer. The link rate is a ceiling; a copy runs at the speed of the slowest element in the path, which on a home or small-office network is usually the storage at one end.

It does not promise its full reach on whatever cabling is already there. The grade of the installed channel is the variable, and it is one a cable tester answers rather than a specification sheet.

It does not promise a cool switch. Ports of this kind run warm, which is why some small switches carry only one or two of them, why several are fanless only up to a stated ambient temperature, and why makers publish a consumption figure for the unit rather than leaving it out.

It does not work with one end upgraded.

What it works alongside

It negotiates down to five, two-and-a-half and one gigabit and below, so a ten-gigabit port is usable from the day it is fitted. It shares its cabling with the Power over Ethernet types. And it appears in transceiver form: modules exist that put a copper ten-gigabit port into a cage otherwise carrying fibre or a direct-attach lead. Those modules are among the most power-hungry a cage can hold, so switch makers state which ones they support — a line worth finding before buying one.

The questions that come up before an order

How far does a ten-gigabit copper link reach?

Over a Category 6A channel, the full hundred metres the cabling standards are built around. Over an installed Category 6 channel, separate published guidance sets a substantially shorter figure, and how short depends on interference from the cables bundled alongside.

Will a ten-gigabit card make a network share ten times faster?

Only if everything else in the path can keep up. A share served from spinning disks, or from a machine doing the encryption in software, finishes at its own speed and the wider link sits idle for most of the transfer.

Last reviewed 9 September 2026