7 Replies Latest reply on Aug 8, 2010 9:06 AM by dvfs

    about intel xeon 5500 power management

    dvfs

      Hi,

      Intel xeon have lots of power management features. NWAIT, power limit, thermal control and so on.

      If I decide to implement a algorithm in firmware level, the specification tells that some register bits should be set. Is this the only way?

      BTW, my final implementation mayby just like the way implmented in BIOS(a setup configuration like Intel speedstep enable). Can you give me some information?

      Thank you!

        • 1. Re: about intel xeon 5500 power management
          dvfs

          Maybe the question is too general, I just wat to know

          the Intel 64 and IA-32 Architectures Software Developer's Manual Volume 3A (and 3B) are for BIOS and OS designers. EFI/UEFI is popular in nowdays.

          The Manual tells that the registers can be set some bits to achieve power managment.  I don't quite sure it is for  BIOS or OS ? Maybe  both.?

          • 2. Re: about intel xeon 5500 power management
            vegan

            The CPU multipler is adjusted as needed due to load. When not loaded the power draw can fall to below 25W.

             

            There is no need to worry about it as its automatic.

             

            I am a developer as well as IT expert, so like I said, it can be ignored.

            • 3. Re: about intel xeon 5500 power management
              dvfs

              Hi vegan,

              I don't think so. Xeon processor did provide the mechanism, but the poliices rely on specific implementation. Like p-state(ACPI) transitions, ondemand(in Linux) policy makes final decision.

              In BIOS configuration, there are some choices about power managment. So I just want to know, if I want to expose user interfaces like that, how can I realize.

              According to my understanding, it is about firmware(BIOS) progarmming, the firmware needs to set register bits like the intel Manual said. Right??

              • 4. Re: about intel xeon 5500 power management
                vegan

                Server and desktop processors have power management, notebook processors are only the most obvious.

                 

                It all goes back to the old EPA energy star program and data center electric bills that keep creeping higher and higher.

                • 5. Re: about intel xeon 5500 power management
                  dvfs

                  HI Vegan,

                  Server and desktop processors have power management(PM)? But most polies are realized in OS level. Your mean Turbo boost?  I just want to use my algorithm to make some comparisons. BTW hp servers use their own firmware implementation.

                  If I decide to implement my algorithm in firmware level.

                  Intel® 64 and IA-32 Architectures Software Developer's Manual Volume 3A: System Programming Guide, Part 1,gives  some info about BIOS design.

                   

                  Both OS and BIOS need to set some register bits to achieve PM, right?

                  The firmware level code is implemented in BIOS(or a new way), right? Thank you.

                  • 6. Re: about intel xeon 5500 power management
                    vegan

                    Applications all interact with the BIOS. Ignore the power management, stick to the solution.

                    • 7. Re: about intel xeon 5500 power management
                      dvfs

                      Application don't care about firmware implemenation detail. Both firmware and OS can achieve PM. That's HP server point.

                      I think OEMs can have their PM implemenation(in firmware level,).It seems that their firmware is not BIOS, only expose a interface in setup configuartion.

                      New BIOS(intel EFI/UEFI) provides  a way to implement flexible PM interface. So I can add my algorithm, right?