9 Replies Latest reply on Aug 20, 2015 9:34 AM by mikec_intel

    NUC BIOS PCIe 1.0a backwards compatibility?


      Hello, Intel,


      This is a topic that's been discussed since Series 7: BIOS support for backwards compatibility with PCIe 1.0/1.0a is problematic on may Intel motherboards. This has been brought up many times in the forums, but the threads all die without resolution. Sylvia_Intel was involved in many of those discussions. If this isn't the place to direct this request, please point me in the right direction.


      My company produces digital signage devices that use various capture cards designed around the SAA7160/NXP7160 audio/video bridge, which sports a PCIe 1.0a interface. We have such cards working with several Intel systems, including a Haswell reference design, but no 1.0a card can be detected by the NUC N54250WYKH Haswell design. The difference between the two Haswells is that the working system employs an AMI BIOS which allows to force PCIe bus speed to GEN1 (or AUTO with "Detect non-compliant device" as an option.) The NUC's Visual BIOS does not support such a setting, and apparently does not conform to the PCIe spec requiring backwards compatibility.


      See: www.tbsdtv.com/forum/viewtopic.php?f=37&t=7521 for one manufacturer's comments concerning the problem.


      This problem affects anyone who plans to use a NUC as an HTPC with video capture capability, since many capture cards are based on the 716x. My company plans to deploy hundreds of these units in FQ4, if we can get the capture cards to work with NUC!


      So, my question is: Is anyone at Intel looking into this issue for the NUC BIOS?  It should be a simple fix, a write during initialization to the Root Complex Link Capabilities Register to limit link speed to GEN1 and width to x1, and maybe some compliance items.  I'd do it myself if I had source to the BIOS ;-)


      PLEASE give us our GEN1 compatibility!.