# Tasks booted to efficiency cores when not in foreground or rendered on the screen

**URL:** <https://discourse.julialang.org/t/tasks-booted-to-efficiency-cores-when-not-in-foreground-or-rendered-on-the-screen/104980>\
**Category:** Performance\
**Created:** [October 15, 2023, 4:10pm UTC](https://discourse.julialang.org/t/tasks-booted-to-efficiency-cores-when-not-in-foreground-or-rendered-on-the-screen/104980 "2023-10-15T16:10:17Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![Di11on](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/di11on/32/6352_2.png) [@Di11on](https://discourse.julialang.org/u/Di11on)\
**Post date:** [October 15, 2023, 4:10pm UTC](https://discourse.julialang.org/t/tasks-booted-to-efficiency-cores-when-not-in-foreground-or-rendered-on-the-screen/104980/1 "2023-10-15T16:10:17Z")

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Hi folks,

I have discovered an issue with my 13900k based machine (I now very much regret the poor choice of a 13900k). Processes run on performance cores when the app/task is in the foreground on the screen - but whenever minimised, tasks are booted to the efficiency cores. For a task to run on performance cores, it has to be in the foreground and drawn on the screen - which is rather a great pain when you have tasks that take a very long time to run and you are not in attendance. The issue is described here, although for a different applicaton: [Forcing performance mode for background app on Intel P/E-core CPU | Page 2 | Windows 11 Forum](https://www.elevenforum.com/t/forcing-performance-mode-for-background-app-on-intel-p-e-core-cpu.15763/page-2)

Some way to force usage of performance cores would be great

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**Author:** ![Di11on](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/di11on/32/6352_2.png) [@Di11on](https://discourse.julialang.org/u/Di11on)\
**Post date:** [October 15, 2023, 5:42pm UTC](https://discourse.julialang.org/t/tasks-booted-to-efficiency-cores-when-not-in-foreground-or-rendered-on-the-screen/104980/2 "2023-10-15T17:42:45Z")

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So, the following, OS level solution works for me in Windows 10:

`powercfg /powerthrottling disable /path "C:\Julia\Julia-1.8.3\bin\julia.exe"`

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**Author:** ![vchuravy](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/vchuravy/32/8_2.png) [@vchuravy](https://discourse.julialang.org/u/vchuravy)\
**Post date:** [October 15, 2023, 7:14pm UTC](https://discourse.julialang.org/t/tasks-booted-to-efficiency-cores-when-not-in-foreground-or-rendered-on-the-screen/104980/3 "2023-10-15T19:14:04Z")

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It may be possible for Julia to use QoS [Quality of Service - Win32 apps | Microsoft Learn](https://learn.microsoft.com/en-us/windows/win32/procthread/quality-of-service) to set policy for the worker threads.