# Do Julia resources improve in background?

**URL:** <https://discourse.julialang.org/t/do-julia-resources-improve-in-background/56776>\
**Category:** New to Julia\
**Created:** [March 9, 2021, 1:08am UTC](https://discourse.julialang.org/t/do-julia-resources-improve-in-background/56776 "2021-03-09T01:08:39Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![HexSpin](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/hexspin/32/19319_2.png) [@HexSpin](https://discourse.julialang.org/u/HexSpin)\
**Post date:** [March 9, 2021, 1:08am UTC](https://discourse.julialang.org/t/do-julia-resources-improve-in-background/56776/1 "2021-03-09T01:08:39Z")

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Code I wrote in December has not undergone significant modification, I’m still using Julia 1.0, and I’ve added no new packages. However, I executed the code over the last few days on the same machine and it appears 4x faster than it was a couple months ago. I’m puzzled. Any thoughts?

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**Author:** ![rdeits](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/rdeits/32/286_2.png) [@rdeits](https://discourse.julialang.org/u/rdeits)\
**Post date:** [March 9, 2021, 2:55am UTC](https://discourse.julialang.org/t/do-julia-resources-improve-in-background/56776/2 "2021-03-09T02:55:20Z")

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Are you using any external packages? Could you perhaps have updated to a newer (and, apparently, faster) version of some package?

Otherwise it’s hard to imagine what’s going on. How did you measure the 4x speed increase?

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**Author:** ![HexSpin](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/hexspin/32/19319_2.png) [@HexSpin](https://discourse.julialang.org/u/HexSpin)\
**Post date:** [March 9, 2021, 3:16pm UTC](https://discourse.julialang.org/t/do-julia-resources-improve-in-background/56776/3 "2021-03-09T15:16:29Z")

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Thanks for your response.

My code calls for:  
import Primes: prime, primes, nextprime  
using Profile, Dates

Which made me wonder about Primes.jl … but I saw no updates…  
As for speed test, my work deals with a large number of iterations - so when I’ve had data sets up to 10^12, they’ve taken more than 12 hours to complete, now the same run takes a bit more than 3 hours. I suppose any change must have happened in my coding, some tweak, that cleared a way to a faster set of calculations.  
Weird, but good weird!  
Thanks,  
Tad

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**Author:** ![rdeits](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/rdeits/32/286_2.png) [@rdeits](https://discourse.julialang.org/u/rdeits)\
**Post date:** [March 9, 2021, 4:02pm UTC](https://discourse.julialang.org/t/do-julia-resources-improve-in-background/56776/4 "2021-03-09T16:02:30Z")

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> [@HexSpin](#):
>
> I suppose any change must have happened in my coding, some tweak, that cleared a way to a faster set of calculations.

Yeah, that’s probably the most likely. That’s why I strongly recommend using `git` (or your favorite version control tool) for every project, even if you have no intention of sharing that work or collaborating on it. Myself from \> 1 month ago might as well be another person, and I’m always grateful to my past self for using `git` to track each change in every project.

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**Author:** ![HexSpin](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/hexspin/32/19319_2.png) [@HexSpin](https://discourse.julialang.org/u/HexSpin)\
**Post date:** [March 9, 2021, 5:29pm UTC](https://discourse.julialang.org/t/do-julia-resources-improve-in-background/56776/5 "2021-03-09T17:29:19Z")

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That’s a good idea. Also, I might go find an old version on my backup and run it. If it runs slow, I the figure out how I inadvertently optimized; runs fast, the mystery continues. 🙂 Thanks for your thoughts.