What are the differences between Cat5, Cat6, and Cat7 Ethernet cables?

(Image: © Jonas DeMuro)

While wireless gear continues to proliferate, the backbone of any network should be connected via wires. Cat is short for "category" and generally denotes the speed the cable is able to carry. We are talking Ethernet cables here, and they offer higher, and more consistent throughput, with less interference, the higher in category you go. These are all characteristics that are especially favorable for gaming, as well as plenty of other networking scenarios such as downloading and streaming media. As your network grows, you pretty much are going to need wires, and, the next choice is exactly which type of wire. These days the choices comes down to a handful of different types.

For years, ask any geek, and the response was often “Cat5,” (although they were mostly referring to the subsequent variant “Cat 5e,” more on that a little later). The number after "Cat" refers to the specification for the wiring. Just a reminder that as you plan out your network, the maximum distance for an Ethernet cable is 100 meters, which is generally not too limiting for most home applications.

This all started when copper telephone cable, originally designed for voice communication, was then repurposed to carry data. These older cables were unshielded, in a twisted pair configuration, and is designated as Cat1. They have a data rate that maxed out at a pokey 1 Mbps, although nobody would use this for a data connection for literally decades at this point.

So what are the different categories?


While there were some standards in between, the next standard to discuss is Cat5. This was a common Ethernet standard, although it is quite outdated at this point. It is notable as the throughput speeds were a nice, round 100 Mbps, at distances up to 100 meters. Nobody should try to run a network on Cat5 these days, nor are the cables even available for purchase.


The subsequent standard is Cat5e, and the “e” stands for “Enhanced.” The more modern Cat5e cable is produced to a higher standard, and is designed to reduce “crosstalk,” which is the phenomenon of unwanted transfer of signals in the wire that reduces throughput. Cat5e can have speeds of 1000 Mbps, and is used in many residential and commercial wired applications for Gigabit Ethernet. This is the slowest cable that anyone should use for a new Ethernet setup, and its primary advantage currently is its lower cost.

There is also a plan to increase the speeds of Cat5e to 5 Gbps over the existing cables, known as the IEEE P802.3bz standard, which also works on Cat6 cabling.


The next standard up is Cat6, which are wound more tightly, add a nylon spline, and shielding to further reduce crosstalk, and reduce interference. While the obvious advantage of Cat6 cabling is that the throughput bumps up to a ridiculous 10 Gbps, but the detail is that these speeds are limited to 55 meter distances, which is shorter than for Cat5 or Cat5e runs, and at longer distances goes back to 1 Gbps. While the speeds are faster for Cat6 on shorter runs, the downside is that the wires are stiffer making them more difficult to bend, and the thicker wires are more difficult to terminate. Cat6 has also traditionally been more expensive, although the price difference compared to Cat5e has lessened over time.


Cat6a is the next variant, and the “a” after the six means “augmented.” These are thicker cables, and are more heavily shielded, which virtually eliminates the crosstalk issue that limits the previous cabling standards. The speeds of Cat6a are 10 Gbps, but the difference is that these lightening speeds are maintained across longer distances of up to 100 meters. These thicker cables with their better shielding are ideal for industrial situations, but lack flexibility that is often needed for a residential deployment.

Cat7 & Beyond

The latest “cable on the block” is Cat7, which is shielded, and requires a GigaGate45 connection. The speeds are wickedly fast, at shorter distances, maxing out at 100 Gbps (!) at < 15 meter distances, and reverting to 10 Gbps at longer distances. There is also a Cat8 standard that is still being finalized, but no gear is currently available, with a targeted throughput of 40 Gbps at longer distances. These “next generation” cable choices of Cat7 and above are more suited to data centers, than residential applications.

Decision time…

Ok, now that we understand the variety of cables, it comes time to choose which to install. Just like there is no best computer or best router for everyone, it comes down to a few variables.

From a cost perspective, Cat5e is the most affordable, Cat6 costs only a little more (and consider that the labor is often the more major expense), and each generation beyond costs considerably more. Also realize that Cat5e is the most flexible around turns and corners, and therefore the most “hassle free” for the DIY installer, with Cat6 being thicker, and so on going up. Finally realize that with the faster speeds likely coming to Cat5e, there is plenty of life in this older standard.

This needs to be balanced against the goal to “future proof” the network. The wiring is a project to install, and the labor costs, when done by professionals, usually exceed the materials cost. There is often a temptation to spend a little more in the hope that the network will outlast the peripherals. For those that want to take this router, Cat6 or Cat6a are good options. 

Also realize that virtually all consumer gear, such as routers, motherboards and Ethernet cards max out at 1000 megabits or 1 Gbps. So for the time being, and likely years to come, the typical user will not be able to take advantage of the 10 Gbps and faster speeds that Cat6a and higher cables are specced for.