Cat7 vs Cat8
Cat8 is TIA-recognised for 25 and 40 Gbps over 30 m in data centres. Cat7 is not recognised, and neither belongs in a domestic installation.
Cat8 is a recognised standard built for one job: very fast links over short distances inside a data centre, up to 40 gigabits over 30 metres. Cat7 is not recognised by the American standards bodies at all, and the RJ45 cable sold under the name does not meet the specification it borrows. Neither is a sensible home purchase. If you are wiring a house or an office and want headroom above Cat6, the answer is Cat6a.
- Verdict:
- Cat8 is a real standard for short data-centre runs; Cat7 is not
Side by side
| Specification | Cat7 | Cat8 |
|---|---|---|
| TIA-recognised | No | Yes |
| Bandwidth | 600 MHz as specified | 2000 MHz |
| Top speed | 10 Gbps | 25 and 40 Gbps |
| Maximum distance at top speed | 100 m as specified | 30 m |
| Connector | GG45 or TERA | RJ45 or purpose-built |
| Intended for | No current mainstream use | Data-centre switch-to-server runs |
Cat8 trades distance for speed
The 30 metre limit is deliberate. Cat8 exists to link a switch to a server a rack or two away, and nothing about it suits a run across a building. Buying it for a house gets you a stiff, expensive cable running at gigabit.
Neither is a home upgrade
Home equipment overwhelmingly tops out at gigabit, occasionally 2.5. Cat6a already exceeds that comfortably, and the cost and handling difficulty of Cat8 buy nothing a household can use.
Buy on what is recognised
Cat5e, Cat6, Cat6a and Cat8 are TIA categories you can hold a supplier to. Cat7 is not, so there is no test a cable must pass to carry the name.
Check before you swap. Batteries with similar dimensions are not always interchangeable. Always verify voltage, chemistry and the requirements printed in your device manual before fitting a replacement.