Data
CAT5e vs CAT6 vs CAT6A
04 Feb 2026 · 5 min read
Category choice fixes the bandwidth of a building for a decade or more. The cost difference between categories is small next to the cost of re-cabling, so the decision should be driven by the design horizon.
What each category actually delivers
CAT5e is specified to 100 MHz and supports 1 Gbps to 100 m, with 2.5GBASE-T achievable over shorter, well-installed channels. CAT6 raises the bandwidth to 250 MHz and supports 10 Gbps to around 55 m. CAT6A is specified to 500 MHz and supports 10 Gbps across the full 100 m channel.
Alien crosstalk is the real differentiator
The reason CAT6A cable is physically larger is alien crosstalk — interference between adjacent cables in a bundle. CAT6A controls it with larger pair separation, a cross-filler or a screen. In dense bundles above racks, this is what keeps 10GBASE-T stable.
That larger outside diameter has consequences: plan pathway fill, bend radius and patch panel depth around it from the start rather than discovering the problem at second fix.
Choosing with confidence
For new commercial fit-outs with a ten-year horizon, CAT6A is the defensible choice. CAT6 remains sensible for shorter horizons and standard office density. CAT5e is best reserved for refurbishment, ancillary devices and low-bandwidth outlets.