# r8168 Realtek gigabit card not running at 1000mbps (solved)

## awalp

Just thought I'd post this in case anyone else had this problem

I spent two hours trying to figure out why my new gigabit pci card was only running at 100mbps.

I was in the process of download realtek's official drivers and installing them when I decided to switch cables.

Solution:

I switched cables to a new Cat6 cable and ethtool instantly said 1000mbps.

EDIT:  Testing the connection, I sent a 400MB file over the network via Samba, onto an XFS share, the computer is only an Athlon XP 2500+, and I was getting up to ~40MB/sec speeds.   320mbps.   Not too bad considering it's only a 2500+ with samba, raid, and XFS overhead.  Definitely almost twice as fast as I was getting at 100mbps.  It probably is CPU/Hardware limited now instead of being network card limited.

I search and found no solution but this same problem all over the internet.

FYI, if your r8169 card is not connecting at gigabit speeds, but only 100mbps, or 10mbps when manually setting ethtool -s eth0 speed 1000.  Try switching to a Cat6 cable.

Amazing solution eh?

I ended up with a 2.6.32 (newer kernel) maybe necessary maybe not, but the stock 2.6.32 driver worked, after installing the cat6 cable.

So the first thing you should check is that you have a Cat6 cable if dealing with gigabit connection problems.  I had an older Cat5 cable (Belkin, high quality).  This Realtek card is really sensitive to cabling I guess so be sure it is Cat6.

The old cable was high quality Cat5 cable 3ft in length.  Apparently the card is really sensitive and the cable was technically not rated for gigabit speeds, even though physically the wires are the same.

----------

## BradN

There's more stuff than you would imagine that goes into constructing high speed cables like that, most critical of which is probably the way wires are twisted to minimize crosstalk (and in fact how much of the end of the cable is untwisted can matter a lot!)

When you get into large datacenters, you might even start worrying about how sharply you make curves in the cables...

All this said, cat5e cables are *supposed* to do gigabit ethernet, and like you found, plain cat5 is no guarantee.  I would imagine some other cards might work with your old cable, but now you have a good card to use to test cables  :Smile: 

----------

