CoreDirector is a free Windows application to keep specified processes from being scheduled to efficient cores (E-cores), thereby keeping them on performant cores (P-cores). This allows improved performance in demanding applications, such as gaming, audio production, video editing, and streaming.

Or get it from the Microsoft Store …

Why is it necessary?

A common challenge with heterogeneous CPUs like Intel 12th+ generation is the occasional undesirable scheduling of threads onto the efficient (E) cores, hampering their performance. This issue arises because most applications have not been, and may never be, updated to provide explicit instructions to the scheduler regarding their thread load types, leaving Windows to rely on educated guesses. But don’t worry, until applications are updated to specify where their threads belong, CoreDirector has you covered!

How does it work?

CoreDirector has several methods of enforcement, from gently disabling Efficiency Mode on target processes, to the little stronger CPU sets, to strict CPU affinities. See the ‘Options’ menu to choose the method(s) of enforcement.

Enforcement Methods:

  • Efficiency Mode OFF
    This method will prevent threads from being put into Efficiency Mode. This serves to prevent them from being automatically scheduled to the E-cores. However, a process can still use the E-cores if its thread count warrants such, or if it specifically chooses to.
  • CPU Affinities
    This method will restrict all threads to the P-cores. The only exception is a process that is intentionally scheduling onto the E-cores. In that case, you can use Process Lasso with ‘Forced Mode’ to overcome the process’s own choices.
  • CPU Sets
    This method is somewhere in between the other two and leaves a lot of the decision to the OS.

Although we recommend using our more powerful Process Lasso software for this purpose, we have made this simplified tool freely available to the community. CoreDirector will run fine alongside Process Lasso.

CoreDirector screenshot

Users may also be interested in our ParkControl software, which now offers power plan heterogenous scheduling settings.

CoreDirector Installer Details


Use /S for silent installation. Valid return codes are:

0 = success (including over-top replacement)
1 = failure or user abort

Revision History

v1.2.2.4 – Jan 9, 2024

  • Minor fixes and enhancements
(1) Add versioninfo resource
(3) Change copyright to 2024

v1.2.1.2 – Dec 21, 2023

  • Minor fixes and enhancements
(1) Fix a handle leak
(1) Adjustments to tray icon registration handling

v1.2.0.4 – Dec 14, 2023

  • Minor fixes and enhancements
(1) Fix an issue where enforcing Efficiency Mode on a suspended process could result in a zombie process under some conditions

v1.1.0.22 – Nov 22, 2023

  • Added dark mode
  • Added full path matching
  • Various cosmetic improvements
(1) Add dark mode
(1) Move Methods submenu to top level, pending further Options additions
(3) Minor cosmetic and string changes
(5) Add matching against full process path
(11) Add version to lower left
(13) Add enforcement status static text control

v1.0.0.2 – Nov 17, 2023 – Initial Release

Discover more from Bitsum

Subscribe to get the latest posts sent to your email.