# Multithreading on RapberryPi4 (arm32 v7 version)

**URL:** <https://discourse.julialang.org/t/multithreading-on-rapberrypi4-arm32-v7-version/29131>\
**Category:** New to Julia\
**Created:** [September 24, 2019, 8:20pm UTC](https://discourse.julialang.org/t/multithreading-on-rapberrypi4-arm32-v7-version/29131 "2019-09-24T20:20:22Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![pavhofman](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/pavhofman/32/10464_2.png) [@pavhofman](https://discourse.julialang.org/u/pavhofman)\
**Post date:** [September 24, 2019, 8:20pm UTC](https://discourse.julialang.org/t/multithreading-on-rapberrypi4-arm32-v7-version/29131/1 "2019-09-24T20:20:23Z")

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Hi,

Please does the “Threads.@threads for” functionality split the loop into threads on RPi (v. 4)? I changed the number of threads to 4 via the env JULIA\_NUM\_THREADS=4, confirmed by Threads.nthreads(). Yet top command shows only one core is running in such loop. On amd64 machines the threading works great.

My code:

```julia
function generateSine(x)
    Threads.@threads for i=1:4
        sin.(x);
    end
end

cnt = Int64(1e7);
x = rand(cnt);
GC.enable(false);
@time generateSine(x)
GC.enable(true);

```

Thanks a lot for any info/hints.

Regards,

Pavel.

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<div class="post-metadata">

**Author:** ![jling](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jling/32/212909_2.png) [@jling](https://discourse.julialang.org/u/jling)\
**Post date:** [September 24, 2019, 8:47pm UTC](https://discourse.julialang.org/t/multithreading-on-rapberrypi4-arm32-v7-version/29131/2 "2019-09-24T20:47:41Z")

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there’s only one process but:

> 391.0% 1.8 0:43.55 julia

it’s using 4 cores.

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<div class="post-metadata">

**Author:** ![pavhofman](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/pavhofman/32/10464_2.png) [@pavhofman](https://discourse.julialang.org/u/pavhofman)\
**Post date:** [September 24, 2019, 9:03pm UTC](https://discourse.julialang.org/t/multithreading-on-rapberrypi4-arm32-v7-version/29131/3 "2019-09-24T21:03:25Z")

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Indeed, I must have been blind.

Thanks a lot!

Pavel.