The Difference Between Cat 5 and Cat 6
Category 6 cable, commonly referred to as Cat 6, is a standardized cable for Gigabit Ethernet and other network physical layers that is backward compatible with the Category 5/5e standards. Cat 6 extended key parameters over Category 5e specifications — the most prominent difference being the frequency at which those key parameters are measured. Compared with Cat 5 and Cat 5e, Cat 6 features more stringent specifications for crosstalk and system noise. The cable standard provides performance of up to 250 MHz (as opposed to up to 100 MHz for Cat5e) and is suitable for 10BASE-T, 100BASE-TX (Fast Ethernet), 1000BASE-T/1000BASE-TX (Gigabit Ethernet) and 10GBASE-T (10-Gigabit Ethernet).
The test limits are different between Category 5e, 6, and 6a. Marketers will sometimes take advantage of those that do not dig into the details. A 350MHz Category 5e rated patch cord will not pass a 250MHz Category 6 test. At 100MHz, a Category 6 cable has a 19.8dB limit vs. a Category 5e cable which has a limit of 22dB. These values are different enough to have a negative impact on your network.
The Cat5e standard has no values above 100MHz. Some marketers will interpret values and project them up to the 250MHz level. That is not an accurate method. The standard is what it is and can’t be changed. If you are looking for Category 6 performance, then quality Category 6 cabling and components are required.