What is the difference between Cat 5e and Cat 6?

This is one of the most common questions we're asked. There are two major differences:

• Signal to noise ratio


• Bandwidth used to test the cable

The first difference is the most important. Cat 6 Cat 6 is twelve times less "noisy", than Cat 5e. When your computer sends data across your network some data packets are lost or corrupted along the way. These packets have to be resent by the system. The better the signal to noise ratio is on your network, the less often this happens.

As computer networks become faster, the signal to noise ratio becomes more important. If the network is racking up packets that must be resent faster than it can resend them, the network may eventually fail or slow to a crawl with the backlog. Using cable and components that have better signal to noise ratios, such as those rated to Cat 6, can help to prevent this potential problem.

As for the testing bandwidth, the official Cat 5e standard calls for testing across a bandwidth of 100 MHz. The Cat 6 standard calls for testing across a bandwidth of 250 MHz. The reality is that most computers and networking equipment only transmit across a frequency range of 100 MHz. (In the future, of course, actual utilization of greater bandwidth may become more common.)

When it comes down to it, however, this particular stat isn't all that important. Many cable companies tout the high bandwidth of their cable. Some even test up to as high as 700 MHz. It sounds great for marketing, but the truth is that the MHz rating is not the same as speed. All cable rated Cat 5e or Cat 6 is capable of Gigabit Ethernet. The MHz rating is just the frequency range used for testing the cable.