# Precompilation of complex code does not make time to first model step faster

**URL:** <https://discourse.julialang.org/t/precompilation-of-complex-code-does-not-make-time-to-first-model-step-faster/92453>\
**Category:** General Usage\
**Tags:** precompilation\
**Created:** [January 3, 2023, 12:22pm UTC](https://discourse.julialang.org/t/precompilation-of-complex-code-does-not-make-time-to-first-model-step-faster/92453 "2023-01-03T12:22:27Z")\
**Posts on this page:** 1\
**Showing post:** 6

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**Author:** ![tim.holy](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/tim.holy/32/52_2.png) [@tim.holy](https://discourse.julialang.org/u/tim.holy)\
**Post date:** [January 3, 2023, 9:16pm UTC](https://discourse.julialang.org/t/precompilation-of-complex-code-does-not-make-time-to-first-model-step-faster/92453/6 "2023-01-03T21:16:16Z")

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No, see the explanation in [Invalidations findings (from a GMT case) - #32 by tim.holy](https://discourse.julialang.org/t/invalidations-findings-from-a-gmt-case/92420/32). If you use `ascend` (see the SnoopCompile docs), you can see how methods used in your workload ultimately trace back to `num_threads`. You can see that invalidation is very expensive, more than 7s of compilation time. (The other one is negligible.)

I think somewhere I saw @Elrod say that `CPUSummary.num_threads` method might be eliminated?

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