3 Replies Latest reply on Sep 15, 2015 10:19 AM by eldata

    Skylake 6700K CPU and Vcore adaptive mode

    eldata

      Hi,

       

      I'm using the above Intel processor, Asus motherboard with Windows 7 OS. Vcore (CPU core voltage) is being set using the adaptive mode in the BIOS and everything works fine until the system wakes from sleep. What then happens is that the Vcore BIOS setting reverts to some lower stock default setting the CPU is apparently programmed to use. The system then becomes unstable.

       

      If either offset or manual mode is used to set Vcore in the BIOS then waking from sleep has no effect on the set voltage, only adaptive mode has the issue. The workaround is therefore to use either offset or manual mode but adaptive is the preferred mode.

       

      Asus claims that there is nothing they can do to address the problem until Intel gives them a CPU microcode update so they can incorporate it in the motherboard's BIOS. Anyone here familiar with this scenario? Is what Asus says making any sense?

        • 1. Re: Skylake 6700K CPU and Vcore adaptive mode
          NiceBlue

          I can copy this behaviour for my ASUS Z170-A as well. I doubt that the microcode of the CPU changes anything. From Skylake onwards the voltage-regulators are sitting on the mainboards again, the mainboard logic puts an adaptive offset to the SVID requested by the CPU. Because adaptive mode is not integrated into the CPU anymore, the mainboard manufacterers needed to put their own logic on the board.

          To confirm this, we would just need somebody with an ASrock Z170 board, who confirms that correct adaptive after standby are set.

          • 2. Re: Skylake 6700K CPU and Vcore adaptive mode
            eldata

            "Because adaptive mode is not integrated into the CPU anymore, the mainboard manufacterers needed to put their own logic on the board."

             

            The logic is obviously there since adaptive works just fine provided one does not go into standby. As to why the CPU should revert to a stock setting, after waking from standby, is not exactly clear and I've been wondering whether it isn't a Windows Intel CPU microcode update that's required. These are released from time to time and I saw a June 2015 one out there but it didn't change anything.

             

            "To confirm this, we would just need somebody with an ASrock Z170 board, who confirms that correct adaptive after standby are set."

             

            ROG and Z170-A boards have this issue. Not certain about the Z170-Deluxe, a fellow has promised to reproduce the issue on his deluxe board later today. If the deluxe has the same problem then I'll check ASRock, Gigabyte and MSI forums. If it doesn't then Asus is just dragging their feet with the lesser boards.

            • 3. Re: Skylake 6700K CPU and Vcore adaptive mode
              eldata

              Asus corrected the issue for the Gene and Hero boards with a BIOS update. One for the Z170-A is probably on the way since they are aware of the issue.