# The same async program run on (Linux+AMD) vs (Win+Intel), over 6x performance difference

**URL:** <https://discourse.julialang.org/t/the-same-async-program-run-on-linux-amd-vs-win-intel-over-6x-performance-difference/133276>\
**Category:** Performance\
**Tags:** multithreading, async\
**Created:** [October 19, 2025, 6:09am UTC](https://discourse.julialang.org/t/the-same-async-program-run-on-linux-amd-vs-win-intel-over-6x-performance-difference/133276 "2025-10-19T06:09:46Z")\
**Posts on this page:** 1\
**Showing post:** 4

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**Author:** ![sgaure](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/sgaure/32/14779_2.png) [@sgaure](https://discourse.julialang.org/u/sgaure)\
**Post date:** [October 19, 2025, 8:58pm UTC](https://discourse.julialang.org/t/the-same-async-program-run-on-linux-amd-vs-win-intel-over-6x-performance-difference/133276/4 "2025-10-19T20:58:45Z")

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There was a recent thread about something similar. I have not used windows, so don’t know anything about whether it’s related.

> [@Performace problems with Windows scheduler and multithreading on mixed core CPUs](https://discourse.julialang.org/t/performace-problems-with-windows-scheduler-and-multithreading-on-mixed-core-cpus/132984):
>
> I have a function with a long running simulation (\> 20 min) and used Threads@spawn to start four of them in parallel. Disappointingly the runtime more than doubled compared to a single instance run. After some digging I found out that the Windows scheduler had placed all four compute threads on the four small Zen 5c CPUs of my laptop while the four big cores were idle… If I set the priority of the julia process to high by hand in the taskmanager the threads are migrated over to the big cores an…

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_[View the full topic](https://discourse.julialang.org/t/the-same-async-program-run-on-linux-amd-vs-win-intel-over-6x-performance-difference/133276)._