How to choose an Ethernet cable

2020-07-01GRANDFULL

Megabits, Cats, and cables get a bit confusing when you are looking at Ethernet cables. Figuring out which works for you without going overboard is hard, but we’re here to help.

We’ve defined these terms and put together tables comparing the benefits and issues with each. We’ll explain what shields do and why you may — or may not — need them. So, start here when figuring out how to choose the best Ethernet cable for your home or work.

How do you choose?

The easiest way to select a cable is to pick one with the range and performance you need.

But what do you need?

Start with the speed of your home internet connection. If you have gigabit internet (1Gbps), an old Ethernet cable will hold you back. If you have a slower connection — perhaps 10 or 20 megabits per second — you’re good with anything Cat 5 or newer.

If you don’t know your internet subscription’s actual speed, connect your PC directly to the modem and load this speed test. Doing so will give you a starting idea of what you’ll need in terms of wired connectivity. If your subscription only supports 50Mbps downloads, purchasing a 1Gbps Ethernet cable is simply overkill — at least for now.

Next, consider the speed needed for your network. This knowledge is irrelevant for most home users, but if you frequently move big files between computers or stream extremely high-bandwidth video, a better Ethernet cable can make a huge difference. If that’s not the case and you only surf the internet’s shallow waters, you don’t need a fast in-homer network.

Finally, consider your router. Many cheap routers only support Ethernet up to 100 megabits per second, so the router will bottleneck anything newer than Cat 5. Even the best home routers rarely support more than gigabit Ethernet, meaning Cat 6a and Cat 7 are of questionable use. If your ISP provides a slow, clunky modem/router combo, request an upgrade or purchase a standalone router with better connectivity.

With all of the above to consider, a Cat 6 cable is the one you’ll most likely need. Many homes can even get away with Cat 5e.

What does ‘Cat’ mean?

When shopping for cables, you may notice they’re nearly always classified as “Cat-5,” “Cat6e,” or something similar. “Cat” simply stands for “Category.” The number that follows indicates the specification version supported by the cable.

A general rule of thumb is that higher numbers represent faster speeds and higher frequencies, measured in megahertz (MHz). As is the case with most technologies, newer cables typically support higher bandwidths, and therefore increased download speeds and faster connections.

Keep in mind that longer Ethernet cables have slower transmission speeds. Cables bought for personal use rarely exceed 100 meters anyway and are unlikely to experience bottlenecked speeds.

Below, you can see the capabilities of each cable type.

Category

Shielding

Max Transmission Speed (at 100 meters)

Max Bandwidth

Cat 3

Unshielded

10 Mbps

16 MHz

Cat 5

Unshielded

10/100 Mbps

100 MHz

Cat 5e

Unshielded

1,000 Mbps / 1 Gbps

100 MHz

Cat 6

Shielded or Unshielded

1,000 Mbps / 1 Gbps

250 MHz

Cat 6a

Shielded

10,000 Mbps / 10 Gbps

500 MHz

Cat 7

Shielded

10,000 Mbps / 10 Gbps

600 MHz

Cat 3 and Cat 5

Both Cat 3 and Cat 5 Ethernet cables are, at this point, obsolete. You’ll still find Cat 5 cables in use, but you should avoid them altogether. They’re slow and discontinued.

Cat 5e

The “e” in Cat 5e stands for “enhanced.” There are no physical differences between Cat 5 and Cat 5e cables. However, manufacturers build Cat 5e cables under more stringent testing standards to eliminate unwanted signal transfers between communication channels (crosstalk). Cat 5e is currently the most commonly used cable, mainly due to its low production cost and support for speeds faster than Cat 5 cables.

Cat 6

Cat 6 cables support higher bandwidths than Cat 5 and Cat 5e cables. They’re more tightly wound too and often outfitted with foil or braided shielding. This shielding protects the twisted pairs of wires inside the Ethernet cable, which helps prevent crosstalk and noise interference. Cat 6 cables technically support speeds up to 10 Gbps, but only do so for up to 55 meters. That speed comes with a price, however, as Cat 6 cables are more expensive than Cat 5 and Cat 5e variants.

Cat 6a

The “a” in Cat 6a stands for “augmented.” Cables based on this standard are a step up from Cat 6 versions by supporting twice the maximum bandwidth. They’re also capable of maintaining higher transmission speeds over longer cable lengths. Cat 6a cables are always shielded, and their sheathing — which is thick enough to completely eliminate crosstalk — makes for a much denser, less flexible cable than Cat 6.

Cat 7

Cat 7 cables support higher bandwidths and significantly faster transmission speeds than Cat 6 cables by utilizing the newest widely available Ethernet technology. They’re proportionally more expensive than other Ethernet cables, though their performance translates to a premium price tag. Cat 7 cables reach up to 100 Gbps at a range of 15 meters, making them an excellent choice for connecting modems or routers directly to your devices. Cat 7 cables are always shielded and use a modified GigaGate45 connector, which is backward compatible with regular Ethernet ports.