Cat5e and Cat6 at a glance
From the outside the two cables are hard to tell apart: both have four twisted pairs under a round jacket, and both use the same RJ45 connectors. The differences are inside the jacket and in what the cable is specified to carry.
| Feature | Cat5e | Cat6 |
|---|---|---|
| Pair separator | None; pairs sit together around a ripcord | Usually a cross-shaped spline |
| Conductor | 24 AWG | 23 AWG |
| Bandwidth | 100 MHz | 250 MHz |
| Speed over 100 m | Up to 2.5 Gbit/s (2.5GBASE-T) | Up to 5 Gbit/s (5GBASE-T) |
| 10 Gbit/s | Not specified | Up to 55 m |
| Outer diameter, Nexlane U/UTP | 5.20 mm | 6.20 mm |
| Best for | 1 Gbit/s homes and light office runs | Multi-gig, PoE cameras and access points, dense bundles |
Inside the jacket: the spline
The easiest way to recognise Cat6 is to look at the end of the cable. Most Cat6 cables have a plastic spline, a cross-shaped divider that runs down the centre and gives each of the four pairs its own channel. Keeping the pairs physically apart reduces crosstalk between them, which is one of the main things that limits how fast a cable can carry data.
Cat5e has no spline. Its pairs sit together around a thin ripcord, which is used to open the jacket and plays no electrical role. Some Cat6 designs meet the standard without a spline, so the spline is typical rather than universal. See why the wires are twisted for how the pairs keep noise out in the first place.
Thicker copper, and why it matters for PoE
Cable conductors are sized in AWG (American Wire Gauge), where a smaller number means a thicker wire. Cat6 typically uses 23 AWG copper and Cat5e 24 AWG; that is the case across our Cat5e and Cat6 ranges.
A thicker conductor has lower resistance, so it loses less power and runs cooler when it carries current. That matters for Power over Ethernet (PoE), which powers cameras, wireless access points and phones through the data cable. With high-power PoE, and in large bundles where heat builds up, Cat6 gives more margin.
The thicker conductors and the spline also make Cat6 a little thicker overall. Our U/UTP versions measure 5.20 mm for Cat5e and 6.20 mm for Cat6, which affects how many cables fit in a conduit or tray.
Speed and bandwidth
Bandwidth is the frequency range a cable is specified and tested to: 100 MHz for Cat5e and 250 MHz for Cat6. More bandwidth gives more headroom for higher data rates.
Both cables carry 1 Gbit/s Ethernet over the full 100 m channel. The IEEE 802.3bz standard added two multi-gig speeds for existing cabling: 2.5 Gbit/s over Cat5e and 5 Gbit/s over Cat6, both at up to 100 m. Cat6 can also carry 10 Gbit/s over shorter runs of up to 55 m. For 10 Gbit/s over the full 100 m, choose Cat6A.
These figures assume a correctly installed link: good terminations, the bend radius respected, and no pairs untwisted further than necessary.
When to choose Cat5e
Cat5e remains a sound choice where 1 Gbit/s is enough and cost and handling matter most.
- Homes and small offices running 1 Gbit/s to computers, TVs and routers
- Light office runs with no plans for multi-gig switches
- Projects where a lower cable cost, a thinner cable and quicker terminations matter most
When to choose Cat6
Cat6 is the better default for new commercial installations, and wherever the cable has to last through the next upgrade of switches and access points.
- Multi-gig links (2.5 or 5 Gbit/s) to Wi-Fi access points and workstations
- PoE cameras, access points and other powered devices, especially with high-power PoE
- Dense bundles in trays and ceilings, where heat and crosstalk build up
- Any job where the walls or ceilings are open anyway: pulling cable again later costs far more than the cable itself
