# @debug has massive performance impact on Windows

**URL:** https://discourse.julialang.org/t/debug-has-massive-performance-impact-on-windows/103974
**Category:** Performance
**Created:** [September 18, 2023, 9:53am UTC](https://discourse.julialang.org/t/debug-has-massive-performance-impact-on-windows/103974 "2023-09-18T09:53:57Z")
**Posts on this page:** 1
**Showing post:** 7

<div class="post-metadata">

### Author: ![ThummeTo](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/thummeto/32/26105_2.png) [@ThummeTo](https://discourse.julialang.org/u/ThummeTo)
#### Post date: [September 18, 2023, 11:32am UTC](https://discourse.julialang.org/t/debug-has-massive-performance-impact-on-windows/103974/7 "2023-09-18T11:32:00Z")

</div>

Hm… so am I doing something wrong?

```julia
Julia Version 1.9.3
Commit bed2cd540a (2023-08-24 14:43 UTC)
Build Info:
  Official https://julialang.org/ release
Platform Info:
  OS: Windows (x86_64-w64-mingw32)
  CPU: 8 × Intel(R) Core(TM) i7-8565U CPU @ 1.80GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-14.0.6 (ORCJIT, skylake)
  Threads: 1 on 8 virtual cores

```

Even in 1.9.3. I have:

```julia
julia> @btime my_sum($x)
  61.876 ns (0 allocations: 0 bytes)
500.0120162080791

julia> @btime my_sum_debug($x)
  479.487 ns (2 allocations: 112 bytes)
500.0120162080791

```

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