4 Replies Latest reply on Nov 6, 2010 10:45 AM by

    High DPC latency caused by onboard Intel NIC 82578DC on Intel DH55HC

    eranrose

      My system is  Intel DH55HC board, i7 860, 8GB RAM, Windows 7 ultimate x64, latest BIOS   TCIBX10H.86A.0039.2010.0722.1419 from 22.07.2010

      Driver for NIC is the latest available fron Intel DL center v 15.3 (Driver  version 11.6.92.0)

      After the computer is running for a while, when I surf or download, the computer slows to a hault, as long as the network activity continues. When it stops, PC retuns to normal.

      After some research I found out that during the slowdown I have very high DPC latencies (>10000 microseconds).

      After some web searching I found a thread http://social.technet.microsoft.com/Forums/en-US/w7itpronetworking/thread/25378207-aaaf-40f2-97fd-302a901ffdb3?prof=required , and used Windows Performance Tools Kit  to track down the problem to NDIS.sys:

      http://img29.imageshack.us/img29/4485/dpcg.jpg

      I added a Realtek 8139 PCI NIC replacing the onboard NIC  and the problem is solved.

       

      This appears to be a bug in the INtel onboard NIC or it's driver, at least for W7 x64

       

      Can anyone confirm? Any ideas how to solve the problem?