Are Ethernet Cables Slowing Your Connection?

Now, here’s the thing. You’ll never see the port’s maximum speed due to network overhead, which is bandwidth used to carry information about the payload (your data) traveling down the line. We use 6% here to give you an idea of real-world speeds, although the percentage changes based on the protocol used to transfer your data.

And yes, it’s quite the rabbit hole. We get it. But Ethernet ports and cables play hand-in-hand. Plug a CAT 6 cable into a Gigabit Ethernet port, and chances are the most you get is 940Mbps. Plug that same cable into a 2.5Gbps Ethernet port, and you still get around 940Mbps—the cable is now your only bottleneck. A CAT 6a cable and newer is best for Multi-Gig Ethernet ports.

If you have an older PC with a Fast Ethernet port, you can work around its limitation by purchasing a USB-to-Ethernet adapter that supports gigabit speeds. The older USB-A 2.0 port supports up to 480Mbps, which is better than a Fast Ethernet connection. However, you should use a USB-A 3.x or USB-C 3.x port, as they support 5,000Mbps (5Gbps) or 10,000Mbps (10Gbps), depending on the port’s configuration.

The bottom line here is to be wary about the Ethernet ports you have and how they affect your connections to other devices and the internet. Don’t expect to use a CAT 6a cable and get a 10 Gbps connection out of a Gigabit Ethernet port.

If you don’t know the maximum speed of your Ethernet port(s), we provide instructions on how to find a port’s speed on a Windows PC or a Mac in our FAQ.