CAT5e

Lets start off with Cat5e… and scrap it. It is expected that 80% of new corporate installs will use Cat6 or Cat6a by the end of 2011; given this trend and massive speed boosts with Cat6 you would (in general) be crazy to instal Cat5 in the walls of a fresh install.

DIFFERENCES BETWEEN CAT6 & CAT6a

Speed

.                                     CAT6           CAT6a
Transfer Rate             1GB             10GB
Frequency                   250Mhz     500Mhz

Price

Price is a big deal.  I was just told by my cable supplier than for 100+ drop installs, bid pricing for Cat6a will come in at about the same price as Cat5e.  In other words, don’t worry about it.

The patch cables can be more expensive, so make sure to include them in your bid process to get the best price.  Also, our engineering contractor informed me that you can use Cat6A patches on Cat6 cables in the wall, but not the other way around… so just get Cat6a for the entire network.

Future

Some people say that Cat6 will eventually be respec’d to officially handly 10GB (and of course in very short runs, it will operate at 10GB now) but given the price difference, why stress over this.

Thickness – Conduit Concerns

A real concern is the thickness of the cable.  Cat6a is noteably thicker than 6 or 5e and that might be an issue for your conduits.

References

You might find THIS and THIS useful