# (Wallclock) Performance degraded when going from 1.11.6 to 1.12

**URL:** <https://discourse.julialang.org/t/wallclock-performance-degraded-when-going-from-1-11-6-to-1-12/133171>\
**Category:** New to Julia\
**Created:** [October 15, 2025, 1:00pm UTC](https://discourse.julialang.org/t/wallclock-performance-degraded-when-going-from-1-11-6-to-1-12/133171 "2025-10-15T13:00:23Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![JJMerelo](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jjmerelo/32/217998_2.png) [@JJMerelo](https://discourse.julialang.org/u/JJMerelo)\
**Post date:** [October 15, 2025, 1:00pm UTC](https://discourse.julialang.org/t/wallclock-performance-degraded-when-going-from-1-11-6-to-1-12/133171/1 "2025-10-15T13:00:23Z")

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I have been working with this repo, [GitHub - cecimerelo/BraveNewAlgorithm.jl](https://github.com/CeciMerelo/BraveNewAlgorithm.jl) and running energy benchmarks, as well as performance benchmarks.  
After upgrading to 1.12, and as measured by an external CLI (pinpoint), the speed has degraded by 10% and the energy consumption by even more, 20%.  
I’m pretty sure this is not a problem with Julia itself. The issue is that I’m measuring startup time, compilation time, as well as the program itself. I would say that it’s the startup time that’s killing this: maybe this version includes more optimized JIT compiler or something, and the actual speed since the script has actually started to the end is actually improving.  
However, this forces me to change methodology of measurement (trying to measure baseline, for instance), which might be major, so I’d like to hedge my bets here and ask before: does this hunch make sense, or actual speed might have always taken a hit for some reason?  
**edit** With the version upgrade I had to upgrade a series of libraries, including Optimization; that shouldn’t impact much since I don’t use it directly.

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**Author:** ![matthias314](https://avatars.discourse-cdn.com/v4/letter/m/a88e4f/32.png) [@matthias314](https://discourse.julialang.org/u/matthias314)\
**Post date:** [October 15, 2025, 1:34pm UTC](https://discourse.julialang.org/t/wallclock-performance-degraded-when-going-from-1-11-6-to-1-12/133171/2 "2025-10-15T13:34:18Z")

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I just want to point out that in [this thread](https://discourse.julialang.org/t/nerd-sniping-can-you-make-this-faster/132793/35) we also noticed a ~10% slowdown with Julia 1.12. In microbenchmarks the difference was even around 40%.

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**Author:** ![JJMerelo](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jjmerelo/32/217998_2.png) [@JJMerelo](https://discourse.julialang.org/u/JJMerelo)\
**Post date:** [October 15, 2025, 3:48pm UTC](https://discourse.julialang.org/t/wallclock-performance-degraded-when-going-from-1-11-6-to-1-12/133171/3 "2025-10-15T15:48:57Z")

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Is that intended? Or just teething pains?

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**Author:** ![paulmelis](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/paulmelis/32/35063_2.png) [@paulmelis](https://discourse.julialang.org/u/paulmelis)\
**Post date:** [October 17, 2025, 10:20am UTC](https://discourse.julialang.org/t/wallclock-performance-degraded-when-going-from-1-11-6-to-1-12/133171/4 "2025-10-17T10:20:13Z")

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> [@JJMerelo](#):
>
> After upgrading to 1.12, and as measured by an external CLI (pinpoint), the speed has degraded by 10% and the energy consumption by even more, 20%.

As an aside, how are you measuring energy usage?

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**Author:** ![JJMerelo](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/jjmerelo/32/217998_2.png) [@JJMerelo](https://discourse.julialang.org/u/JJMerelo)\
**Post date:** [October 17, 2025, 10:52am UTC](https://discourse.julialang.org/t/wallclock-performance-degraded-when-going-from-1-11-6-to-1-12/133171/5 "2025-10-17T10:52:45Z")

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I’m using for the time being `pinpoint`. I’m just now getting around to differentiating between the baseline (energy spent in compilation and so on) and energy actually spent in the execution of the workload. Check out [GitHub - cecimerelo/BraveNewAlgorithm.jl](https://github.com/CeciMerelo/BraveNewAlgorithm.jl) for the experiments and [GitHub - JJ/brave-new-green-algorithm: Evaluating energy requirements of a Brave new Algorithm in Julia](https://github.com/JJ/brave-new-green-algorithm) for the WIP paper