Topic: How to enable dynamic CPU speeds in Windows?

[devnullius]

I just installed a fresh Win Server 2012 R2 system. One of the things I noticed was that the CPU speeds in task manager would fluctuate and go up or down depending on the load of the machine. This is a good thing: it saves (a lot of) energy.

Because my system was unstable I changed a few things, among others I reset the BIOS to safe values. The stability problems are gone now (still tracking down what solved it) BUT the dynamic CPU speeds are also gone :/

I went back to the bios and enabled the following, but still no dynamic cpu speeds...

GART error reporting: disabled
Microcode Update: Enabled
Secure Virtual Machine Mode Enabled
PowerNow Enabled
C State Mode C6
PowerCap P-staet 0
HPC Mode Disabled (I tested Enabled too, just in case, but this did not solve it)
CPB Mode Auto
CPU DownCore Mode Disabled (I don't fully understand this one, but I'm afraid I will effectively disable 1 or more cores with this)
C1E Support Auto
Clock Spread Spectrum Enabled


Any help appreciated while I try to track this one down ;p I'll be looking at http://serverfault.com/a/196329 next...

UPDATE: still not solved, only thing I could find with Google was this: Disable CPU Scaling in Windows Server (http://serverfault.com/questions/196301/disable-cpu-scaling-in-windows-server-2008-r2)

HELP! :S

Devvie

EDIT: found this article: problem is installing Hyper-V, not me resetting the BIOS!! https://social.technet.microsoft.com/Forums/windows/en-US/6f383b2a-3a4a-472f-a966-cda0ce646e37/hyperv-windows-8-cpu-power-management-problem?forum=w8itprogeneral

Will read next

I can confirm this is happening with Windows 8 Enterprise RTM with the Hyper-V role installed.
Dell E6430 BIOS A03 (current as of September 6th, 2012)
Intel 3rd Gen Core i5-3210M
SpeedStep Enabled in BIOS
CPU power state and throttle down working fine as verified with Task Manager without the Hyper-V role installed.  Intel Turbo Boost also functioning fine without Hyper-V role installed.
With the Hyper-V role installed the CPU speed as reported in Task Manager stays at the Maximum speed regardless. Intel Turbo Boost not functioning either as reported by Task Manager.
As noted earlier, the bug could be with Hyper-V or maybe Task Manager itself.  Just here to confirm the behavior.
-Weaver

Sigh...

I have experienced the same behavior with Windows 8 RTM.
I have a workstation with two 16 core 6272 2.1GHz Opterons.  Without Hyper-V, almost all the cores park and the processors idle at 700mhz - 1.4 ghz and the machine consumes 85 watts.  Turbo mode works perfectly, pushing the processors routinely to 3Ghz so long as only half the cores are busy.  Between 50% and 100% load, the machine runs at 2.5 - 2.1 Ghz.  Power management is working as it should; however, once the Hyper-V role is enabled, all cores are pegged at 2.1 Ghz and idle power usage soars to 185 watts.  Cores never boost beyond 2.1 Ghz and also never idle to lesser frequencies.  As you watch Task Manager, CPU processing jumps around all 32 cores.  So at idle, every core is slightly busy yet at peak frequency.  This behavior stays even after multiple reboots over multiple days.
Removing the Hyper-V Role sets everything back to normal, power management is restored, turbo mode works again, and idle power usage returns to 85 watts.
I have been forced to fall back to using the less ideal type 2 hypervisor VMWare Player and Workstation to run my virtual machines.
I have been hoping for a Windows Update patch to resolve this power mangement / thread scheduler issue; but i have not seen any yet....

After some more reading, solution in the reply

[devnullius]

The solution... (not tested yet, but verified with CPU-ID: in *my* case it indeed is a GUI bug from Task Manager - a bug that has been explained as the result of a 'feature'*)

DON'T WORRY! TESTED ON A I7 LAPTOP AND FOUND OUT BY READING FREQUENCIES THAT ALTHOUGH IT DISABLES YOUR POWER MANAGEMENT FEATURES, IT DOESN'T AFFECT TURBO BOOST. I HAVE A WORKAROUND FOR THOSE WHO WANT TO HAVE A POWER SAVING PROFILE OR "STEP DOWN PROFILES":
BEFORE ENABLING HYPER-V(OR IF YOU HAVE IT ENABLED GO TO CONTROL PANEL>>>UNINSTALL A PROGRAM>>>TURN WINDOWS FEATURES ON OR OFF>>>UNCHECK THE HYPER-V BOX>>>OK,IT MAY NEED A REBOOT) CREATE POWER MANAGEMENT PLANS FROM THE POWER MANAGEMENT SECTION IN CONTROL PANEL. FOR EXAMPLE I HAVE 5 POWER PLANS, 2 POWER SAVERS, 1 BALANCED, AND 2 HIGH PERFORMANCE ONES- ONE THAT ALLOWS "FULL THROTTLE", I MEAN MAXIMUM PERFORMANCE, AND ONE THAT PREVENTS OVERHEATING, THAT NEEDS TURBO BOOST OFF.THIS IS DONE BY SETTING MAXIMUM ALLOWED PROCESSOR USAGE TO 99% IN THE ADVANCED SETTINGS,SO THAT YOU DON'T HAVE TO GO TO THE BIOS SETTINGS ALL THE TIME.---THEN ENABLE HYPER-V, AND SWITCH BETWEEN THE PLANS YOU'VE JUST CREATED.
PLEASE NOTE THAT THE TASK MANAGER WILL ONLY SHOW THE BASE FREQUENCY OF YOUR PORCESSOR, ALTHOUGH UTILITIES LIKE HWINFO, INTEL XTREME TUNING UTILITY, AND TURBO BOOST MONITOR FROM INTEL WILL SHOW THE REAL CLOCK FREQUENCY. THERE IS PROBABLY A BUG IN THE TASK MANAGER, OR MAYBE THE PERF COUNTERS FOR TURBO BOOST ARE DISABLED OR SOMETHING.

I'm glad I have found this thread as I was wondering what's going on with Hyper-V and power management. I installed it since VM workstation is causing instant clock_watchdog_timeout BSOD for no reason. Nonetheless this "no power management" thing is silly as it means more power consumption for no valid reason, which is especially annoying on a laptop! I will set the service to on-demand and reboot after using Hyper-V since that's the only solution offered by MS at this point..
the solution being "sc config hvboot start= demand".

It seems that speedstep is still working behind the scenes.
The explanation short: taskmanager is showing you a virtualised cpu consumption.
If you monitor cpu usage/speed/power consumption via 3rd party tool like CPU-Z, then it will show you a completely different picture.
http://www.nspyre.nl/blogs/3178/Windows8-Hyper-V-V3-SpeedStep
for full explanation

That's all from https://social.technet.microsoft.com/Forums/windows/en-US/6f383b2a-3a4a-472f-a966-cda0ce646e37/hyperv-windows-8-cpu-power-management-problem?forum=w8itprogeneral

[jheysen]

Funny thing is that I got the same set of problems when I installed Hyper-V on my laptop, now I uninstalled it and VirtualBox can't Virtualize :/

[devnullius]

Funny thing is that I got the same set of problems when I installed Hyper-V on my laptop, now I uninstalled it and VirtualBox can't Virtualize :/

:/ doesn't sound good - new topic maybe? Though a quick google (without further details) did not help me...