Hello all

I am very new here. This is my first post. My question is what could be causing the latency on my system? It's an Intel i7 2600 CPU, 6G of ram with the above mentioned network card.

To the best of my knowledge this machine hasn't had latency issues until just recent. I am running Ubuntu 10.04.3 LTS on it. The kernel is Linux version 2.6.32-37-generic dated Dec 2, 2011. Ping times from a computer on the same switch to the problem machine are in the 90 ms range yet from other computers they are in the 0.040 - 0.060 ms range. I'm able to transfer files at about 170-190 KB/s to and from this problem computer. The network drivers appear to be loading properly. Network traffic is at a minimum so there isn't an issue with bandwidth.

ethtool output:

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 pause frame use: No
Advertised auto-negotiation: Yes
Link partner advertised link modes: Not reported
Link partner advertised pause frame use: No
Link partner advertised auto-negotiation: No
Speed: 1000Mb/s
Duplex: Full
Port: Twisted Pair
PHYAD: 0
Transceiver: internal
Auto-negotiation: on
MDI-X: Unknown
Supports Wake-on: umbg
Wake-on: g
Current message level: 0x00000007 (7)
Link detected: yes


lspci:

lspci |grep Ethernet
09:00.0 Ethernet controller: Intel Corporation 82541PI Gigabit Ethernet Controller (rev 05)

Thanks for your input in advance.

Replace the switch first or at least the cables. The slots go bad.

I've checked the switch and cables by connection a couple of computers including the one that's acting up to a spare switch using different cables. There is no change in the ping times. Also to clarify, the network card is an Intel Pro/1000 GT.

Thanks

Are you saying there is a known issue with the Intel cards as of a few months ago? Those cards are some of the better choices. You said it was fine and now is not. Any item could cause it from changes to software or driver settings or other loads on the system or failure of hardware. You have to diag it somehow.

Then connect this system directly to a known good one and test again. Take everything out of except the cable.

Swap the card out.

I have narrowed down the source of the problem. It is not cables or drivers. When the system is booted with the 2.6.32-37-generic kernel the ping times start in the 90 ms range and if you let it run long enough it drops to 1 ms range. When you boot with 2.6.32-36-generic kernel, the previous version, you get normal ping times of less than 1 ms. This appears to be some kind of kernel issue.

Thanks

I am sorry to stir up an old thread but can you please tell me what you did to fix this issue? I have the exact same problem with the same card. The only difference is I am using kernel 3.2.0-23 with Ubuntu 12.04. Did you ever find a real solution to the problem? I have been watching the ping times cycle from 99.5 to 1.5ms and I would love to be able to use these cards again. (I have 2 of them)

Any help with this would be much appreciated

Thanks,