2 Replies Latest reply on Mar 19, 2013 4:58 PM by Victor_Intel

    DX79SI - USB3 - spread spectrum clocking

    Sebastian

      Hi there,

      I have trouble with the DX79SI Mainboard and some external USB3 devices. For some USB3.0 devices, such as Cypress FX3,  it is mandatory to disable the Spread spectrum clocking on host side, in order to work correctly. How can I disable the Spread spectrum Clocking in the latest BIOS version 0553(2012/10/27)? In case it is not possible, is this function available in an old bios version or with another tool?

      Best regards,

      Sebastian

        • 1. Re: DX79SI - USB3 - spread spectrum clocking
          Sebastian

          Dear Intel support team,

           

          I am still looking for an answer.

          In the meantime we found some additional information:

          Source: EE Publishers - USB 3.0: Shaking up the status quo

           

          "Some motherboards improperly implement centre-spread SSC clocking, which violates the USB 3.0 specification requirements. Centre-spread profiles are centered on the nominal frequency and are modulated above and below by equal amounts, for example +2500/-2500 ppm. Most USB 3.0 devices are not compatible with systems that improperly implement center-spread SSC. When consumers purchase host add-in cards and add them to a system that has a noncompliant system clock, they will be disappointed."


          How did you realise the SSC on the DX79SI motherboard?
          How can I disable the Spread spectrum Clocking? In case it is not possible, is this function available in an old bios version or with another tool?


          Best regards,

          Sebastian

          • 2. Re: DX79SI - USB3 - spread spectrum clocking
            Victor_Intel

            Hello Sebastian,

             

            The Intel(R) Desktop Board DX79SI is compliant with the USB 3.0 standards and there is no option to disable
            Spread spectrum Clocking or has been or earlier BIOS versions.

             

            Regards.