Cat5e vs Cat6 vs Cat6a: which Ethernet cable do you need?

For any internet plan up to 1 Gbps, Cat5e is enough, and Cat6 gives you no extra speed. Cat6 and Cat6a only matter for multi-gig: Cat6 carries 5 Gbps over a full run and 10 Gbps over shorter ones, and Cat6a carries 10 Gbps over the full 100 m (328 ft). If your wired speed is stuck near 100 Mbps, the cable category is rarely the reason. A damaged cable or a slow port usually is.

What each category supports

These are the standard Ethernet speeds each category is rated for, from Intel's Ethernet cable guide and the Ethernet Alliance's 10GBASE-T paper:

Speed	Cat5e	Cat6	Cat6a
1 Gbps	100 m	100 m	100 m
2.5 Gbps	100 m	100 m	100 m
5 Gbps	Not rated in Intel's table	100 m	100 m
10 Gbps	No	Up to 55 m	100 m

A home cable run is almost never longer than 100 m, so the length limit matters less than it looks. Within a house, the useful takeaway is simpler:

• Cat5e: fine for any plan up to 1 Gbps, and for 2.5 Gbps.
• Cat6: fine up to 5 Gbps, and 10 Gbps on runs up to 55 m (180 ft).
• Cat6a: the safe choice if you're wiring walls for 10 Gbps.

The 2.5 and 5 Gbps speeds were added later, in the IEEE 802.3bz standard, specifically so older Cat5e and Cat6 wiring could carry more than 1 Gbps. The NBASE-T Alliance (now part of the Ethernet Alliance) designed them for existing cables, which is good news if your walls are already wired with Cat5e.

Does a better cable make your internet faster?

Only if the old cable was the limit. A Cat6 cable on a 500 Mbps plan gives the same result as a Cat5e cable, because both already handle 1 Gbps. Upgrading doesn't lower ping either. Signals travel through either cable at essentially the same speed, and a few meters of copper adds no delay you could measure in a game.

So "best Ethernet cable for gaming" has a dull answer: any cable that's Cat5e or better, undamaged and properly terminated. The win comes from plugging in at all. Ethernet avoids the Wi-Fi interference and retries that cause lag spikes. Why Wi-Fi is slower than Ethernet covers that gap, and good ping for gaming covers what to aim for once you're wired.

On a gigabit plan, don't expect a test to show 1,000 Mbps even with a perfect cable. Overhead takes a cut. Verizon, for example, describes its 1 Gig Fios tier as "up to 940/880 Mbps" on a wired connection.

When you need Cat6 or Cat6a

Buy Cat6 or Cat6a when every part of the chain is faster than 1 Gbps:

1. Your plan is above 1 Gbps (2 Gbps, 5 Gbps and so on).
2. Your modem or router has a 2.5 Gbps, 5 Gbps or 10 Gbps port.
3. Your computer has a matching port or adapter.

If any of these is 1 Gbps, the whole link runs at 1 Gbps and Cat5e does the job. Many routers still have one multi-gig port and several gigabit ones, so check which port you plug into. If you're choosing new hardware for a fast plan, how to choose a router covers which ports to look for.

If you're running cable inside walls, buy Cat6a anyway. The price difference is small compared with opening a wall again in ten years.

How to read the markings on a cable

The category is printed along the jacket every few feet. A typical marking looks like "CAT6 UTP 24AWG 4PR". Here's what to look for:

• CAT5e, CAT6 or CAT6A. If there's no category printed at all, assume the worst.
• UTP or STP/FTP. UTP is unshielded and fine for homes. Shielded cable helps in electrically noisy spots but needs proper grounding to help.
• 4PR. Four twisted pairs. Gigabit and faster need all four.
• CCA. Copper-clad aluminum. It's cheaper but weaker, breaks more easily and doesn't meet the category standards. Choose solid or stranded copper instead.

Patch cables you buy for a desk or console are stranded and flexible. Cable sold on a reel for walls is usually solid. Both work.

The cable that caps you at 100 Mbps

This is a common Ethernet problem, and it looks like this: your plan is 300 Mbps or more, your Wi-Fi gets close to it, but the wired computer tops out in the mid-90s on a speed test.

That number is a clue. Older 100 Mbps Ethernet needs only two of the four wire pairs. Gigabit needs all four. If one pair is broken, crushed or badly crimped, the devices quietly fall back to 100 Mbps instead of failing. Overhead then takes the result to the mid-90s.

To confirm it, check the link speed your computer reports:

• Windows: Settings > Network & internet > Ethernet, then look for the link speed.
• Mac: System Settings > Network > Ethernet > Details > Hardware.

If it says 100 Mbps, work through these in order:

1. Swap the cable. Try one you know works. Cables crushed under doors or furniture, or with a broken clip, are the usual culprits.
2. Try another router port. Some ISP gateways and older routers have one or more 100 Mbps ports.
3. Check adapters and docks. Many cheap USB Ethernet adapters and older laptop docks are 100 Mbps only. Look for "Gigabit" or "10/100/1000" on the label.
4. Check wall jacks. If the run goes through a wall plate, a single loose wire at either end can drop the link to 100 Mbps. Testing with a short patch cable straight to the router tells you whether the wall wiring is the problem.

If the link shows 1 Gbps but your speed is still low, the cable is fine and the problem is elsewhere. Why a speed test reads below your plan and the step-by-step slow internet checklist cover the next things to check.