1 Reply Latest reply on Mar 5, 2013 5:16 PM by Dan_Intel

    DH77EB BIOS update for missing rdrand instruction

    yamcenutzer

      HI

      As I already posted in the processors discussion group, I have yet another problem with my DH77EB. It does not contain a microcode update for the missing rdrand instruction. Running the cpu in a non Intel board (e.g. Asus z77pro v) enables the rdrand instruction. So once again, Intels own BIOS is missing features, that they have obviously passed on to others. See below quote about the processor bug that should be fixed by microcode.

       

      My Bios version 099.

      Any ideas when/how the fix is going to come?

       

      Cheers,

       

       

       

      FYI: From the Specupdate for IB processosrs (jan 2013):

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      BV54. The RDRAND Instruction Will Not Execute as Expected

      Problem:

      On processors that support the RDRAND instruction, that capability should be reported via the setting of CPUID.01H:ECX.RDRAND[bit 30]. Due to this erratum, that bit will not be set, and the execution of the RDRAND instruction will result in a #UD exception.

       

      Implication:

      Software will not be able to utilize the RDRAND instruction

       

      Workaround:

      It is possible for the BIOS to contain a workaround for this erratum to report RDRAND as present via CPUID and allow proper execution of RDRAND.

       

      Status:

      For the steppings affected, see the Summary Tables of Changes.

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