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I was wondering if—aside from the settings listed in the Change advance power settings—do the pre-made power plans change any other hidden settings like throttling, CPU clock speed, etc?

For example, if I change all the settings for Balanced to be the same as High Performance, would they be identical?

There are a few similar questions here:

Giacomo1968
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3 Answers3

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Yes, there are indeed many power plan attributes that are not exposed in the UI. The system stores the three default power plan templates in the registry, and any modifications or custom plans are stored as overrides to the template. Any setting not shown in the UI is inherited directly from the template. One of the hidden settings, 'Personality', will tell you which of the three templates it is.

High performance will keep cpu clocks at near-max even when idle, wasting power and producing heat (servers probably use this). Power saver will stay at lowest clock speed unless under sustained high load, so your ingame framerate and video playback will suffer (might be good for laptops on battery power). Balanced is the only practical choice for normal use, since it will rapidly adjust the cpu clock according to current demand.

The defaults for processor power settings are at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\PowerSettings\54533251-82be-4824-96c1-47b60b740d00. There's a FriendlyName and Description on every key, but some are not very helpful. The MSDN article for win7, "Processor power policy on Windows", describes the Processor power management section.

Searching for some of the setting names on the web turns up more interesting info. The blog post "How to Unlock The Hidden Features of Processor Power Management" reveals that the settings can be un-hidden from the UI by altering the Attribute option in the template:
powercfg -attributes Group_GUID_Here Setting_GUID_Here -ATTRIB_HIDE

I went through the registry tree and wrote a script that unhides the hidden ones: powercfg-win7-all-settings.bat. One oddity is that the Personality setting will not show in the UI even if unhidden. Also, note that the options window will look really ugly if you unhide all the settings. That's why there's the bit in the script that lets you hide everything again.

Obviously, Microsoft doesn't want users casually fiddling with these settings because there are a lot of non-obvious side-effects to changing them, and they may be heavily interdependent. On the other hand, picking the wrong power profile template has a huge impact on system behavior (performance, power usage). The user will think that they've seen all the options the UI has to offer. Meanwhile, their computer will run slowly, or keep overheating, and they won't be able to tell why.

theultramage
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There is a free software named "PowerSettingsExplorer". It can show you the differences in power plans and allow you to change every hidden setting.

Kyo
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The name associated with the pre-set power plans is just an unique string value; you can change the pre-set Balanced profile to feel like the High Performance profile by altering the advanced power settings. Windows uses a GUID from powercfg to save your custom settings and this is actually used when altering the advanced power settings. Please note that if you have a Professional version of Windows, you can use gpedit.msc (type it in Run to run it) and there in Computer Configuration --> Administrative Templates --> System --> Power management you can find the explanation:

GPEDIT.MSC

Emil Nechifor
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