Originally Posted by craigwhiteside
cat 5 is rated for 100mb and up, cat5e is for 1000mb but isnt meant for those speeds, cat 6 is meant for 1000mb connections because of its higher frequencies, and cat 7 is essentially cat 6 but with extra shielding and can reach further distances than cat 5,5e and 6
All these "CATx" specifications are minimum specification requirements. They are usually written at 100m of cable... ie. for extended office wiring.
I run unshielded CAT5e cable at Gb speeds without a problem. But note that cables are on average only 3m. Some 30cm, some 10m, but on average 3m or less. With short cables you are unlikely to have problems using CAT5 or CAT5e at GB speeds, so dont worry.
NOTE: when I say unshielded, I mean, in practice, non-perfect shielding. The cable has the metal foil in it, but with home-made cable lengths with manually connected RJ45 plugs, there is usually no, or poor connection of the cable shield to the metal plug. Home-cut cables are NEVER as good as a factory sealed RJ45 plug with proper shielding.