2 Replies Latest reply on Jun 4, 2010 2:37 PM by gbonneau

    Cannot enable I/OAT with 82576 on Windows Server 2008 R2


      I have a motherboard (Supermicro) with Intel 5520 Chipset+ICH10 with dual socket configuration populated with 2 Xeon 5670. The motherboard design has the Intel 82576 network chip. I installed Windows 2008 R2 and proceeded to install the network driver using the latest driver available on Intel site. When I use the IOATCHK utility provided on the Network Connection CD the utility complains that the hardware doesn't support I/OAT. Yet my understanding is that it should.


      What wrong?

        • 1. Re: Cannot enable I/OAT with 82576 on Windows Server 2008 R2

          From http://downloadmirror.intel.com/12193/eng/readme.txt

          Intel I/OAT requires the following to operate on Microsoft Windows 
          Operating Systems:
          - A server chipset and BIOS that are Intel I/OAT capable
          - An adapter or network connection that is Intel I/OAT-capable
             - The RSS advanced setting must be enabled
             - Under TCP/IP Offloading Options, both Offload Receive IP Checksum and
               Offload Receive TCP Checksum must be enabled.


          I'd double-check the BIOS on the board, make sure it's enabled, and make sure you've altered the two NIC settings.

          • 2. Re: Cannot enable I/OAT with 82576 on Windows Server 2008 R2

            I had already checked this list before asking. But I did double check again to make sure  I didn't forget anything. I meet all these requirement. The BIOS does have the IOAT setting to enable.


            Yet the IOATCHK utility does say that the hardware doesn't support IOAT.


            However using the command:


            netsh int tcp show global


            I got this report :


            C:\Users\Administrator>netsh int tcp show global
            Querying active state...

            TCP Global Parameters
            Receive-Side Scaling State          : enabled
            Chimney Offload State                 : automatic
            NetDMA State                            : enabled
            Direct Cache Acess (DCA)           : disabled
            Receive Window Auto-Tuning Level    : normal
            Add-On Congestion Control Provider  : ctcp
            ECN Capability                      : disabled
            RFC 1323 Timestamps                 : disabled



            The DCA is disabled but the BIOS has the DCA set to enable. Could this be the problem ?


            Here there another means beside IOATCHK to check if IOAT is enables?