CAT5e vs. CAT6 Bandwidth
Both CAT5e and CAT6 can handle speeds of up to 1000 Mbps, or a Gigabit per second. This is more than sufficient for the speed of by far the most internet connections. The chance is small that you currently have an internet connection with which you can achieve up to 500 Mbps speed.
The main difference between CAT5e and CAT6 cable lies within the bandwidth, the cable can support for data transfer. CAT6 cables are designed for operating frequencies up to 250 MHz, compared to 100 Mhz for CAT5e. This means that a CAT6 cable can process more data at the same time. Think of it as the difference between a 2- and a 4-lane highway. On both you can drive the same speed, but a 4-lane highway can handle much more traffic at the same time.
CAT5e vs. CAT6 Speed
Because CAT6 cables perform up to 250 MHz which is more than twice that of CAT5e cables (100 Mhz), they offer speeds up to 10GBASE-T or 10-Gigabit Ethernet, whereas CAT5e cables can support up to 1GBASE-T or 1-Gigabit Ethernet.
CAT5e vs. CAT6 Crosstalk
CAT5e and CAT6 are both twisted pair cables. Both use copper wires, with typically 4 twisted pairs (8 wires) per cable. In the past, the 250 MHz performance provided by CAT6 was often achieved by using a nylon spline in the wiring, which isolated each of the four twisted pairs, making the cable rigid. Nowadays, CAT6 cables are more flexible, using other methods to reduce noise.
Regardless of whether a spline is used, CAT6 features more stringent specifications for crosstalk and system noise. Not only does CAT6 provide significantly lower interference or Near-End Crosstalk (NEXT) in the transmission compared to CAT5e, it also improves Equal-Level Far-End Crosstalk (ELFEXT), Return Loss (RL) and Insertion Loss (IL). The result is less system noise, fewer errors and higher data transmission rates.
CAT5e vs. CAT6 Maximum Length
Both CAT5e and CAT6 offer lengths of up to 100 m per network segment. The maximum achievable speeds will never be met beyond this length. This can result in a slow or failing connection, or even no connection at all. If it is required to cover distances longer than 100 m, the signal can be amplified with repeaters or switches.
When used for 10GBASE-T, the maximum length of a CAT6 cable reduces to 55 m. After this distance the rate drops to 1GBASE-T. To be able to run 10GBASE-T over the full 100 m, it is advised to use CAT6A also called Augmented Category 6 cable.