CPU Parking on Hybrid Processors?

[lylybrown]

Hi everyone, I've been experimenting with ParkControl to manage CPU parking on my PC, which uses an Intel Alder Lake processor with both Performance and Efficiency cores. I'm curious how ParkControl distinguishes between these cores when applying parking settings. Does it treat all cores equally, or can it differentiate between P-cores and E-cores? Any insights or detailed explanations would be greatly appreciated!

[Jeremy Collake]

The system is responsible for that differentiation. In Windows 10, power plan attributes exist to control parking for each of the distinct processor classes (E-core, P-core), and ParkControl will show those. Unfortunately, in Windows 11 those power plan attributes are not available, so precise control over which class of processor cores get parked is not supported.

[emelialucass]

In Windows 11, the attributes for power plans are not accessible, meaning that precise management of which class of processor cores can be parked is not feasible.
 

[KirkH420]

The use of ParkControl basically requires the use of PowerSettingsExplorer. Without it, you will not be able to configure the Performance Overlays which become exposed by using ParkControl to set a power profile. (This is why you believe these settings are missing from Win11). (This is also why your machine keeps falling asleep when you set the high performance overlays despite the fact that you think you disabled sleep on AC power).

With the aforementioned in mind, I have noticed that ParkControl seems to read the default values incorrectly from the registry when Show Efficiency Class is enabled. When I enable this, ParkControl reports 32% Ecore (reg default: 0%) and the Pcore 0% (reg default 50%). Then sometimes ParkControl just decides to set Pcore at 21% but pressing 'restore defaults' brings it back to default 50%.

ParkControl also cannot maintain the Park settings. Next boot, Windows will restore it to whatever it feels like. Dynamic boost definitely does not work on 2 Hybrid CPUs that I've tried it on (also a raptor lake). It will switch power profiles as expected, but the park settings will not follow and the tray icon stays red.

Another thing that I only just now noticed; parkcontrol cannot maintain the park settings if I select the Balanced power profile. The park and scale settings will only stick for about 5 seconds and then are reverted (probably by windows). However, it's interesting to note that the settings do stick fine if I enable one of the performance overlays.

I suspect these things may be inherent to how Windows handles hybrid CPUs, rather than these being problems with ParkControl. Hopefully some of this info is useful to someone.

*I do wish that ParkControl's "restore defaults" feature would not reset every single power setting to default. So if you did disable Sleep, you'll need to do it again if you press that plus any other power related setting.

[Jeremy Collake]

We had not realized that use of performance overlays was popular. We'll work to extend support for them! As to the other issues, I'll report back as we assess them.

Thanks for the feedback!