0 Replies Latest reply on Apr 15, 2010 5:47 AM by Russ_at_Omnitek

    PCI Express Link Negotation in x16 slot of GM45

    Green Belt



      I have a GM45 PICMG 1.3 Motherboard that is fitted with a x16 Express Slot. We are using the integrated graphics device and placing a PCIe x4 commercial video card into the PEG slot to use it as a general purpose PCI-Express port.


      We are finding that aprox 1 time in every 10 reboots or power-on events the PCI-Express link is coming up as a x1 link rather than the desired x4 link.


      Using a CATC PCI-Express protocol analyzer. i can see that the GM45 is attempting to negotiate to x4, but then decides to revert to only a x1 link. The CATC Bus analyzer shows no protocol errors and when the AddInCard is being fully loaded there are never any Bus errors either.


      The only problem exists in the initial link-training of the GM45 to the AddinCard.


      Has anybody else experienced this or tried using the PEG port with anything other than a x16 Graphics Card?


      Thanks, Russ Hicks.