What's the use of the "GPU Preference Policy" power parameter ?

Dear forum readers,

This (hidden) parameter's value can be set either through powercfg.exe, or through the advanced power settings. To see it in the advanced power settings, you have to unhide this parameter, with the following command line :

Code:

powercfg.exe /attributes sub_graphics gpupreferencepolicy -attrib_hide

This parameter has two possible values : None (default), and Low power.

So I set it to Low power, but I've yet to see any changes : GPU selection seems to still work the same. Is it an unused parameter, or one that doesn't apply to my hardware ? Fwiw, I've a laptop w/ Intel UHD Graphics as iGPU and an Nvidia Geforce RTX 3070 as dGPU (and Windows version is 20H2, build 19042.928).

Optimus | Technology | GeForce

Are you running any programs that invoke the nVidia GPU?

I have no personal experience with Optimus. It has always seemed to me as a clever idea that has lots of nuisance potential.

Yes I do run such programs. In fact, those programs don't explicitly invoke the dGPU, but it's the MS Hybrid Graphics system that does the GPU autoselect, exactly like before I set this parameter it seems.

I've noticed that the parameter is set to None in all default power plans, except for the Power Saving plan, where it's set to Low Power when on battery.

NovHak said:

Yes I do run such programs. In fact, those programs don't explicitly invoke the dGPU, but it's the MS Hybrid Graphics system that does the GPU autoselect, exactly like before I set this parameter it seems.

I've noticed that the parameter is set to None in all default power plans, except for the Power Saving plan, where it's set to Low Power when on battery.

It appears that you know a great deal more about this than I ever will. Sorry that I can't answer your question.

Windows 10 is getting new GPU controls for power users

bobkn said:

It appears that you know a great deal more about this than I ever will. Sorry that I can't answer your question.

Don't be sorry about that, especially considering there are many things that are undocumented on Windows, and thus remain largely unknown because of its closed software model... among which that GPU Preference Policy parameter.

Concerning the MS Hybrid Graphics system, there's some documentation though.

chepstowboy1953 said:

Windows 10 is getting new GPU controls for power users

This isn't new, but it provides no way to specify a global GPU preference. The Nvidia control panel gives the option to set the iGPU as the default, but even then, there are still some actions that trigger the use of the dGPU, which is annoying... I suppose if I hooked/replaced or remove references to the Nvidia driver dList dll, I may be able to achieve the goal of not using the dGPU unless explicitly requested, but I'm worried about possible unexpected consequences.

That being said, I didn't ask about it here since I think nobody has the answer, I'm only looking for more info about the GPU Preferences Policy parameter !