Slow net speed on Intel DG965OT motherb. with 82566DC NIC

English Network/Internet
1

Hi

I already posted this in the Hardware forum, but I’m posting it here because this place might be more appropriate. And also because I didn’t get any replies :slight_smile:

I’m running Suse 10.2 on my Intel DG950OT motherboard. The network card on this motherboard is Intel 82566DC.

For some reason I can only get 100Mb/s connecting when connecting to 1Gb/s switch, but when connecting straight to another computer I get a 1Gb/s connection. The odd thing is that just some weeks ago I was able to get a 1Gb/s connectiong to this same switch! As far as I know, no settings have been changed on my Suse that might affect this.

I’we tested the switch thorougly and changed the cables, but still I only get 100Mb/s speed.

Anyone know what might be causing this?

Here is the output of ehttools, if that’s of any help:

baldur:/home/terminal # ethtool eth0
Settings for eth0:
Supported ports: TP ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Full
Advertised auto-negotiation: Yes
Speed: 100Mb/s
Duplex: Full
Port: Twisted Pair
PHYAD: 0
Transceiver: internal
Auto-negotiation: on
Supports Wake-on: umbg
Wake-on: g
Current message level: 0x00000007 (7)
Link detected: yes

baldur:/home/terminal # ethtool -i eth0
driver: e1000
version: 7.1.9-k4-NAPI
firmware-version: 1.1-0
bus-info: 0000:00:19.0

regards
Frímann Kjerúlf

2

Normally the NIC autonegotiates the best speed with the switch. You say you have changed the cable. Have you also changed the port on the switch? It could be that you have a fault on that port.

Also you say it works with a crossover cable to another machine. How does the output of ethtools on that setup differ from this setup and does this shed any light on the problem?

3

I’we tried many differnt cables, I’we tried all the ports. I’we even tried another switch, which worked even worse. Got 10Mb/s on that one.

When I connect the adapter to another computer the only difference I can see is that ethtools tells me that the speed is 1000Mb/s.

I’we also tried running suse from a live CD and also booted up in windows. Got the same speed there, so I’m giving up on this adapter, probably something wrong with it.

4

Yes, I would probably reach the same conclusion too. Maybe a failing transceiver.