What cable for Gigabit

My house is wired with Cat 5 originally bought when 100mbps was the max. I now have Gigabit LANs on the computers and am toying with a Gigabit switch to link to the router to get faster LAN transfers. Will I need to upgrade cables?

Provided all 4 pairs in each cable are functioning properly, you shouldnt need to recable anything. Cat5E will do gigabit.

Trouble is I think it's only Cat5 not 5e bought around 1998, it has shielding but can't find any markings yet. Just tried linking the gigabit ports and they only connected at 100 mbs. Hmmm.

If you have a cable tester (or if you've got a multimeter and have some patience) you could check to make sure all the wires are working properly?
Cat5 *should* be good for gigabit over short-ish distances.

Define short? I have a run of about 30 feet.

I'd be surprised if it didnt run at gig over 30 feet with all pairs functioning, but I've no experience with gig on cat5 (non enhanced) personally. As far as I'm aware it should work, over what distance I'm not sure, but 30 feet isnt much really.
Are you able to check the continuity on the cables?

Cat 5 won't even run gigabit over a metre. Believe me, I've tried it. You need cat 5E at least.

I can't think that's correct. IEEE 802.3 states 1000BASE-T over Cat5 or Cat5e is possible.

Edited by summat (Sun 13-Dec-09 21:24:43)

That may well be what the specifications say. Unfortunately it seems that the cables can't read. Every Cat 5 cable that I have tried (with all four wires connected) steadfastly refuses to connect at gigabit speeds, but reverts to 100 megabit. I may just have been unlucky.

To the OP - why don't you try setting up a direct connection, over your wiring, between two gigabit devices and see whether they connect at gigabit or not? Theory is fine, but you can't beat experimentation.

Gigagbit over Cat 5/5e requires 4 pairs to be connected, i.e. 8 wires.