Short Thread Policy Switcher

A lightweight Windows utility to control the Heterogeneous Short Running Thread Scheduling Policy. This hidden power setting can significantly affect game performance, especially when using PBO on AMD X3D CPUs.

Features

• GUI Version: Visual interface with radio buttons, auto-refresh, and system tray-friendly operation
• Console Version: Minimal background hotkey daemon
• PowerShell Scripts: Quick one-click policy switching with auto-elevation
• Global Hotkeys: Switch policies from anywhere without opening the app
• Audio Feedback: Different beep tones for each policy setting

Policy Options

0. All processors - Short threads can run on any core
1. Performant processors - Short threads run only on P-cores
2. Prefer performant processors - Short threads prefer P-cores
3. Efficient processors - Short threads run only on E-cores
4. Prefer efficient processors - Short threads prefer E-cores
5. Automatic - Let Windows decide

Usage

GUI Version (Recommended)

Run policy_switcher_gui.exe as Administrator. The GUI shows:

• Current policy setting (auto-refreshes every 2 seconds)
• Radio buttons to select and apply any policy
• Status information

Hotkeys (work even when minimized):

• ALT+X - Cycle through all 6 policies
• ALT+V - Cycle through performance policies (All → Performant → Prefer Performant)

Console Version

Run policy_switcher.exe as Administrator for background hotkey daemon:

• ALT+X - Cycle through all 6 policies
• ALT+V - Cycle through performance policies

PowerShell Scripts

Right-click and "Run as Administrator" or just double-click (auto-elevates):

• set_all_processors.ps1 - Set to "All processors" (recommended for gaming)
• set_prefer_performant.ps1 - Set to "Prefer performant processors"

Requirements

• Administrator privileges (required to modify power settings)

Building

GUI Version

build_gui.bat

Requires either:

• Visual Studio (cl.exe)
• MinGW-w64 (gcc, windres)

Console Version

build.bat

Requires either cl.exe or gcc in PATH.

Download

Prefer not to build? Download pre-compiled executables from the Releases tab.

Technical Details

Uses the Windows Power Management API (powrprof.dll) directly - no dependency on powercfg.exe.

Modifies the Windows power setting:

• Subgroup GUID: 54533251-82be-4824-96c1-47b60b740d00 (Processor power management)
• Setting GUID: bae08b81-2d5e-4688-ad6a-13243356654b (Heterogeneous short running thread scheduling policy)

You can find more details on the current hypothesis on how this affects FPS here: https://x.com/bardozVAL/status/1999931009119162572