increasing latency on idle box with ASUS P4B533VM board

[Arjan van der Oest]

Hi,

I've build a new P4 box (1.8Ghz, 512MB mem) based upon a ASUS P4B533VM
motherboard. This board has an Intel 845G chipset and onboard 10/100
mbit/s LAN (fxp driver).

When connected directly to a gateway (in my case an Extreme BD10k) I
observe the following behaviour: a ping to the gateway starts around
1ms and slowly increases in steps of .1 or .2ms to around 10ms. Then
it suddenly drops back to 1ms and the process starts all over again.

I've tried a different NIC (3com, xl driver), new cabling, new
switchport and all gives me the same result. My other labbox (a AMD
2000 XP+ with 3com PCI nic) connected to the same router is showing
normal latency. This gives me the feeling it's some sort of timing
issue on the P4's motherboard itself.

Has anyone seen this before? I've searched the archives and found
little on this topic. Any tips/hints where I can seach for further
clues?

Thanks,

Arjan