# Julia 1.5.1 slows down when running multiple instances in parallel

**URL:** <https://discourse.julialang.org/t/julia-1-5-1-slows-down-when-running-multiple-instances-in-parallel/45934>\
**Category:** Performance\
**Tags:** question\
**Created:** [September 2, 2020, 7:09am UTC](https://discourse.julialang.org/t/julia-1-5-1-slows-down-when-running-multiple-instances-in-parallel/45934 "2020-09-02T07:09:13Z")\
**Posts on this page:** 1\
**Showing post:** 5

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**Author:** ![oheil](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/oheil/32/220745_2.png) [@oheil](https://discourse.julialang.org/u/oheil)\
**Post date:** [September 2, 2020, 9:41am UTC](https://discourse.julialang.org/t/julia-1-5-1-slows-down-when-running-multiple-instances-in-parallel/45934/5 "2020-09-02T09:41:49Z")

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I think you are refering to this:

> [@ANN: Parallel \`for\` loops in FLoops.jl with composable and extensible fold-based API](https://discourse.julialang.org/t/ann-parallel-for-loops-in-floops-jl-with-composable-and-extensible-fold-based-api/45390):
>
> A while ago I posted [FLoops.jl RFC](https://discourse.julialang.org/t/rfc-ann-floops-jl-fast-generic-for-loops-foldl-for-humans/37876) that demonstrates alternative for loop framework on top of [Transducers.jl](https://github.com/JuliaFolds/Transducers.jl). FLoops.jl lets users write fast for loops over complex data structures. Since it received quite positive reactions [\*1], it made me think that it might be nice to provide a nice syntax sugar that can give people imperative style feeling on top of functional style composable framework. In particular, I’ve been trying to expose the parallel computing part of Transducers.jl via FLoops.jl…

> **[GitHub - JuliaFolds/FLoops.jl: Fast sequential, threaded, and distributed...](https://github.com/JuliaFolds/FLoops.jl)**
>
> Fast sequential, threaded, and distributed for-loops for Julia—fold for humans™ - GitHub - JuliaFolds/FLoops.jl: Fast sequential, threaded, and distributed for-loops for Julia—fold for humans™

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