LAN speed differences between Cat5e and Cat6/6e cables?

From what I heard, cat5e ethernet cables are fully capable of supporting gigabit ethernet at full speed. However, I have also heard that gigabit speeds are not fully unlocked until you use cat6 or cat6e cables.

Can someone explain that the differences are between these specifications, and under what circumstances would I care about using a cat6/6e cable? Or is cat5e indeed capable of taking full advantage of all that gigabit ethernet has to offer?

Thanks.

Solution 1:

Gigabit Ethernet is really pushing the limit of Cat5e cabling. Cat6 is superior to Cat5e when it comes to insertion loss, near end crosstalk (NEXT), return loss, and equal level far end crosstalk (ELFEXT).

Consequently, Gigabit Ethernet over Cat6 could be marginally faster than Cat5e, by the amount of errors produced over Cat5e, even though the networking equipment on either end still operates at the same 1 Gbit. This difference will vary based on other factors in your environment, and also networking equipment. In real world terms, the difference is probably too small too measure without sophisticated tools, and so small as to be made non-existent when other delays introduced by operating systems, switches, routers, and end-user applications are considered.

Most companies are installing Cat6 now for new installations (some reports say as much as 90%). That is mainly for future proofing, since the labor to run cabling can often exceed the cost of cabling itself. I would recommend Cat6 for all new installations, but not to replace existing Cat5e.