# Using Threads.@spawn with BLAS.set\_num\_threads

**URL:** <https://discourse.julialang.org/t/using-threads-spawn-with-blas-set-num-threads/139865>\
**Category:** General Usage\
**Created:** [October 6, 2026, 8:51pm UTC](https://discourse.julialang.org/t/using-threads-spawn-with-blas-set-num-threads/139865 "2026-10-06T20:51:27Z")\
**Posts on this page:** 1\
**Showing post:** 3

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**Author:** ![Boris](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/boris/32/3306_2.png) [@Boris](https://discourse.julialang.org/u/Boris)\
**Post date:** [October 7, 2026, 12:34pm UTC](https://discourse.julialang.org/t/using-threads-spawn-with-blas-set-num-threads/139865/3 "2026-10-07T12:34:14Z")

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I recently took a [course focusing on parallelism](https://discourse.julialang.org/t/ann-training-course-julia-for-hpc-in-stuttgart-germany-on-sep-29-oct-2-2026/137435) in Julia and we had a discussion about this and we saw a [similar pattern in one exercise](https://github.com/carstenbauer/JuliaHLRS26/blob/main/exercises/Day2/3_dense_matmul/dense_matmul.ipynb).

As far as I understood, you might gain from reducing the BLAS threads when you use your own parallel program because you are competing for the same resources.

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