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Our LAN is based on a Cat 5 cable, while computers are running on a 100mbs NIC.

I was wondering what speed should I expect upgrading NICs and hub/switch to Gigabit.

Eventually should I replace the patch panel and patch cord cables too?

Thank you

Riccardo
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1 Answers1

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You need CAT5E to attain gigabit speed.

CAT5 does not support 1000BASE-T (=gigabit). There are some exceptions - it is then marked on the cable that it supports it, i.e. "verified for gigabit ethernet".

aairey
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  • I see some users have successfully used Gigabit over Cat 5, probably not reaching full Giganit speed. I wonder if attempting this would completely fail (failing negotiation?) or would simply gain lower speeds? That is, reaching 400/500mbs could be worth it... – Riccardo Oct 02 '14 at 08:35
  • could you comment on my comment? Thanks! – Riccardo Oct 02 '14 at 09:32
  • It will not "fail" as such, but I think it will just drop to 100BASE-T. Worth a try, though :) You'l have to replace your switches first anyway. If you consider updating your cabling, go for CAT6 or CAT6A, they are often cheaper than CAT5E (probably because of the demand). – aairey Oct 02 '14 at 09:35
  • Arhhh... the question is if the NICs configured forcedly to Gigabit will allow network traffic at lower speeds (possibly higher than 100 mbps) or if data transmission will be refused completely.... – Riccardo Oct 02 '14 at 09:41
  • If your switch at the other end is set to 100BASE-T it will fail completely. If it is set to autosensing or fixed on 1000BASE-T, I am not sure. Worth a test :) Here is a nice [paper](http://www.eetimes.com/document.asp?doc_id=1205868) on the topic, your Physical layer needs to be set up appropriately. – aairey Oct 02 '14 at 09:43
  • Oh well, it's just a bunch of dollars for a 5 port switch.... I'll have a go, the community may benefit from this experiment :-) Thanks again – Riccardo Oct 02 '14 at 09:53
  • Purely anecdotal, but I have a 30m run of CAT 5 from my switch to router; perfectly happy running at 1000 BaseTX. – Tetsujin Oct 02 '14 at 10:53
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    I could successfully connect multiple computers using the old CAT 5 cables. Effective throughput is limited to 350 Mb/s uplink and 280 Mb/s downlink. Not too bad, and I still have the choice to change cables! – Riccardo Oct 20 '14 at 14:26