TweakScheduler

Now Part of Process Lasso

TweakScheduler

Tune how Windows shares CPU time between apps. TweakScheduler adjusts the Win32PrioritySeparation registry value, which controls whether the foreground app (the one with focus) gets longer CPU time slices than background processes, and if so, by how much.

Download Process Lasso

In Process Lasso, choose Windows Scheduler Settings from the Tools menu (in older versions, Options > Tools).

TweakScheduler with its interval length, fixed or variable interval and foreground boost choices, and the resulting bitmask

The Settings

Three Choices, One Registry Value

Each choice sets part of Win32PrioritySeparation, and TweakScheduler shows the resulting bitmask.

Interval Length

Short or long CPU time slices, or let Windows choose.

Fixed or Variable

With fixed intervals, every process gets slices of the same length. Variable intervals let the foreground app get longer ones.

Foreground Boost

With variable intervals, how much longer the foreground app’s slices are: double (2:1), triple (3:1) or no boost (1:1).

Defaults

What Windows Chooses

With the defaults (“Let the operating system choose”), Windows Server gives foreground and background processes equal time slices, while other editions of Windows give the foreground app longer ones. TweakScheduler shows what Windows chooses on your PC.

For details on the registry value, see Microsoft’s Win32PrioritySeparation documentation (PDF).