Core parking: why Windows puts your cores to sleep and when to stop it

Frost LIVECPUProUndo: YesUpdated Oct 8, 2026View as Markdown

Short answer

Updated Oct 8, 2026

Core parking lets Windows idle unused CPU cores to save power, and waking them takes time. Disabling it is applied through powercfg against the active power scheme rather than a single registry value. The effect is on frame-time consistency, not average FPS: it removes the small stall when a parked core is needed suddenly.

In the app

Disable CPU Core ParkingPRO

Command

powercfg /SETACVALUEINDEX SCHEME_CURRENT SUB_PROCESSOR 0cc5b647-c1df-4637-891a-dec35c318583 10powercfg /SETACVALUEINDEX SCHEME_CURRENT SUB_PROCESSOR 0cc5b647-c1df-4637-891a-dec35c318583 100

What the switch writes. Your current value may differ. 2 more changes below.

What it does

Windows parks cores it believes are not needed, dropping them to a low-power state. Unparking is fast but not instant.

In a game that suddenly needs more threads, like a shader compile, a physics spike or a new area loading, that unparking delay lands inside a frame, and you feel it as a hitch rather than a lower average.

When it helps, and when it hurts

When it helps

Flatter frame times on CPUs with many cores, where parking is most aggressive.
Removes a class of intermittent stutter that does not show up in average FPS at all.
Most visible in CPU-bound competitive games.

When it hurts

Higher idle power draw and more heat, which matters on laptops and small-form-factor builds.
On modern Windows with the Best performance power mode, much of this is already handled: the marginal gain is smaller than older guides suggest.

What it writes

Exactly what the switch changes, read from the app's source. Switching it off is what the app writes when you turn the tweak off again.

With the tweak · CMD

powercfg /SETACVALUEINDEX SCHEME_CURRENT SUB_PROCESSOR 0cc5b647-c1df-4637-891a-dec35c318583 100
powercfg /SETACVALUEINDEX SCHEME_CURRENT SUB_PROCESSOR ea062031-0e34-4ff1-9b6d-eb1059334028 100
powercfg /S SCHEME_CURRENT

powercfg /SETACVALUEINDEX SCHEME_CURRENT SUB_PROCESSOR 0cc5b647-c1df-4637-891a-dec35c318583 100: Keeps every core unparked when plugged in (minimum unparked cores: 100 percent).
powercfg /SETACVALUEINDEX SCHEME_CURRENT SUB_PROCESSOR ea062031-0e34-4ff1-9b6d-eb1059334028 100: Lets every core stay unparked when plugged in (maximum unparked cores: 100 percent).
powercfg /S SCHEME_CURRENT: Re-applies the active power scheme so the changed core-parking attributes take effect immediately.

Switching it off · CMD

powercfg /SETACVALUEINDEX SCHEME_CURRENT SUB_PROCESSOR 0cc5b647-c1df-4637-891a-dec35c318583 10
powercfg /SETACVALUEINDEX SCHEME_CURRENT SUB_PROCESSOR ea062031-0e34-4ff1-9b6d-eb1059334028 100
powercfg /S SCHEME_CURRENT

From the app's source (core_parking_off.hpp), app 2.0.0, checked Oct 8, 2026.

How to undo it

In the app: Yes

Switching it off sets core parking to typical Balanced values (10 and 100 percent), which may not match your power plan.

Set the two core-parking values back to your power plan's defaults and re-apply the plan. Switching it off in Frozen Tweaks sets them to typical Balanced values, 10 and 100 percent, which may not match your plan, because custom and OEM power schemes frequently differ.

Changing several settings at once? The app's Make a restore point button, on every plan, makes a Windows restore point before you start.