Cat6 vs Cat6A: Which Cable Do You Actually Need?

Most of our customers do not know the difference between Cat6 and Cat6A, and that is fine. They are not supposed to. What we do owe them is a straight answer when it is time to pull cable through ceilings and floors, because once it is in, it is in. Replacing cable later is the most expensive thing on a job sheet.

So here is the short version. Cat6 will run gigabit Ethernet up to 100 metres without breaking a sweat. Cat6A will do 10 gigabit Ethernet over the same 100 metres. The cable is a bit thicker, the jacks are a bit chunkier, and the price per metre is roughly 20 to 30 percent more. That is the whole technical story.

What the numbers actually mean

Bandwidth on Cat6 is rated at 250 MHz. Cat6A doubles that to 500 MHz. In real-world terms, that extra headroom is what lets Cat6A carry 10GbE the full distance and shrug off interference from other cables running alongside it. Cat6 can do 10GbE too, but only over short runs of about 37 to 55 metres. Anything longer and you drop back to gigabit.

If your network kit is gigabit today, you might think that makes Cat6 fine. It does. The question is whether your network kit will still be gigabit five years from now, and that is where the maths starts to favour Cat6A.

When Cat6 still makes sense

We still install Cat6 on plenty of jobs. The places where it is the right call:

• Small offices and shops with fewer than ten users where the budget is tight
• Refurbishments where we are just patching a few extra outlets into an existing Cat6 install
• Temporary installations or short-term leases where futureproofing is not the priority
• Buildings where the cable runs are short and you are unlikely to ever need 10GbE

If any of those describe you, Cat6 is fine. We will Fluke-test it on the way out the door and certify the install just like any Cat6A job.

When you should be on Cat6A

For new builds, fit-outs and anything where the cable is going behind plasterboard or above a ceiling tile you are not planning to lift again, Cat6A is what we recommend. Reasons:

• Wi-Fi 6 and Wi-Fi 7 access points already use 2.5GbE and 5GbE uplinks. Cat6A handles them without thinking about it.
• Camera systems are shifting to 4K and AI analytics. The bandwidth on a busy NVR can saturate gigabit fast.
• Network kit is dropping in price every year. The 10GbE switch you cannot justify today will be standard in five years.
• The cable cost is the smallest part of a structured cabling job. Labour, containment and certification are the same either way.

What about restaurants and retail?

Hospitality and retail sites are a special case because tills, kitchen displays, card terminals and CCTV all hammer the network at the same time during service. We default to Cat6A in any new restaurant fit-out for that reason. The PDQ cannot drop. The kitchen printer cannot stutter. Cat6A gives you the headroom you need on a Friday night when your access point, four cameras and three tills are all on the same switch.

What about warehouses?

Warehouses are where Cat6A pays off the most. Long cable runs, lots of metal racking causing reflections, and a future likely to involve robots, sensors and high-resolution cameras. We have done warehouse installs where the customer initially wanted Cat6 to save a few hundred pounds, then came back two years later wanting 10GbE for a new WMS. That second visit always costs more than the saving did.

Our default answer

If we are quoting a new install today and you have not asked us to economise, we put Cat6A on the line. The price difference on a typical office or restaurant fit-out is small enough that it is worth it for the peace of mind alone. You will not regret installing Cat6A. People do regret installing Cat6 when they need to upgrade five years later.

Whatever we install, it is Fluke DSX tested on the way out and you get the certification report. That is the bit that proves the cable will actually deliver what it says on the tin.