CAT5 vs CAT5e vs CAT6

CAT5 cable supports 10BASE-T and 100BASE-T network standards, that is it supports networks running at 10 Mbps or 100 Mbps.

CAT5e is an enhanced version of Cat5 that adds specifications for crosstalk. Cat5e cable is backwards compatible so can be used in any application in which you would normally use Cat5 cable. However, the added specifications of Cat5e enable it to support Gigabit Ethernet (1000BASE-T), or networks running at 1000 Mbps.

Crosstalk is the "bleeding" of signals between one cable into another, due to a process called induction. This effect can result in slow network transfer speeds, and can even completely block the transfer of signals over the cable. With CAT5e cable crosstalk has been greatly reduced.

Bandwidth - Bandwidth is the information carrying capacity. The greater the bandwidth of a system, the faster it is able to push data across a network. Cat5 is rated at 100Mhz while Cat5e is rated at 350Mhz. This coupled with other more stringent specifications makes Cat5e ideally suited for networks which plan to operate at Gigabit Ethernet speeds.

Bottom Line - If you have Gigabit Ethernet computers and network switches, go with Cat5e.

CAT6 - The difference between CAT5e and CAT6 is in the transmission performance. While CAT5e can support gigabit speeds, CAT6 is certified to handle gigabit Ethernet. CAT6 is typically used in environments that are unfriendly to twisted pair cabling, for example areas that have lots of interference from power lines, lights, and manufacturing equipment. 

Before you upgrade to CAT6, think about your network components, are they gigabit rated? In order to achieve true Gigabit Ethernet speeds, every server, workstation, switch must be gigabit rated.