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Asus P8Z77-V and Intel 82579V LAN only connects at 100MB

  • NICs
  • Routers
  • LAN
  • Components
Last response: in Components
December 1, 2012 9:37:25 PM

Just installed my new system, and was looking around, and I noticed that my LAN is only connecting to my router at a 100MB connection, not the gigabit connection it should be (shows both in network connections, and the orange LED on the back of the motherboard (green is gigabit) )

I have a Linksys WRT610Nv2 router, which is a gigabit router, and the computer has the gigabit lan port. Another computer connected to the same router is connecting fine, as is my cable modem which shows it connected to the router as gigabit.

Also, according to my router, it says that the computer is connected via 10/100 port also.

The cable isn't kinked really, so not sure it's the cable. I also installed the latest drivers from the asus website ( , Intel(R) Gigabit Ethernet Driver V17.2.0.0 for Windows XP/7/8 32bit & 64bit.(WHQL) 157,81 (MBytes) 2012.10.08 update).

Is there something I am missing? Not sure what the problem is.

Edit: I just installed the router right after the install..the old router want a gigabit router...not sure if this matters

More about : asus p8z77 intel 82579v lan connects 100mb

Best solution

December 1, 2012 10:00:38 PM

Process of elimination:-
Try a different cable, the one you have may be bad even though it's not kinked.
Try a different port on your router, it may be the port that's bad.
Let us know how you got on.
December 1, 2012 10:28:54 PM

looks like it was a bad cable. I had already tried different ports on the router. But just did a quick run to the store to test out the cable. All is good now. Didn't think it was the cable, was only a couple years old.

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December 1, 2012 10:29:03 PM

Best answer selected by whiteazn.
January 1, 2013 2:23:37 PM

I had a similar problem with my 82579V Gigabit NIC refusing to negotiate above 100Mb/s.
This was in a computer-to-computer LAN, direct connection with single cable, no router.
After trying various cables, I've come to the conclusion (completely empirically) :
. it is not related to cable quality (Cat5e and Cat6 work equally well)
. it is related to cable core connections - straight-through or crossover.
if straight-through, it connects but not above 100Mb/s.
if crossover, it connects at 1Gb/s

I guess the MDIX logic for doing the crossover itself (for the straightthrough cable)
conflicts with the higher speed.

So - check your cable core connections are correct for the NIC on the other end.