No luck. I tried those drivers and the DPC spikes and noise appear after a day of running.
The problem occurs when copying files over the network or with internet usage. I'm using DPC Latency Checker v1.2 from http://www.thesycon.de/eng/home.shtml I don't think it logs, but it's clear to see the levels that are fine initially but gradually creep up into the red, until the system is rebooted.
I've tried 3 different BIOS updates, and tried network adapters in all available PCI slots (don't have a PCI express nic to try - is there such a thing?)
Thanks,
Darryl
Darryl Gittins