# Adding MORE packages can result in speedup (and other strangeness)

**URL:** https://discourse.julialang.org/t/adding-more-packages-can-result-in-speedup-and-other-strangeness/45715
**Category:** General Usage
**Created:** [August 29, 2020, 12:18am UTC](https://discourse.julialang.org/t/adding-more-packages-can-result-in-speedup-and-other-strangeness/45715 "2020-08-29T00:18:33Z")
**Posts on this page:** 1
**Page:** 1

<div class="post-metadata">

### Author: ![Palli](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/palli/32/3380_2.png) [@Palli](https://discourse.julialang.org/u/Palli)
#### Post date: [August 29, 2020, 12:18am UTC](https://discourse.julialang.org/t/adding-more-packages-can-result-in-speedup-and-other-strangeness/45715/1 "2020-08-29T00:18:33Z")

</div>

A.  
Speedup and lower memory use, adding the first package:

```julia
$ julia -q
julia> @time using DataValues, CSVFiles, ExcelFiles, StatFiles, ParquetFiles, DataFrames, VegaLite
 10.102168 seconds (14.07 M allocations: 842.677 MiB, 3.38% gc time)

vs:
$ julia -q
julia> @time using CSVFiles, ExcelFiles, StatFiles, ParquetFiles, DataFrames, VegaLite
 10.522314 seconds (14.33 M allocations: 857.825 MiB, 3.36% gc time)

$ julia -q
julia> @time using CSVFiles, ExcelFiles, StatFiles, ParquetFiles, DataFrames, VegaLite
 10.528817 seconds (14.33 M allocations: 857.912 MiB, 3.54% gc time)

julia> versioninfo()
Julia Version 1.6.0-DEV.735
Commit f047d7ffc7 (2020-08-27 00:54 UTC)
Platform Info:
  OS: Linux (x86_64-pc-linux-gnu)
  CPU: Intel(R) Xeon(R) CPU D-1541 @ 2.10GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-9.0.1 (ORCJIT, broadwell)

```

Is this a strange bug? I’ve heard people shying away from adding packages, but the trend is clear. Julia scales well.

I would love to hear a good explanation (I know about invalidations, but they may hurt, also help?).

B.  
The order of the packages can also matter for speed.

Opposite order of `using` the SAME packages can mean 20% fewer allocations, i.e. allocating 207 fewer MB (19%) and 1.8 sec. quicker (i.e. takes 21% off):

[https://github.com/queryverse/Queryverse.jl/issues/43](https://github.com/queryverse/Queryverse.jl/issues/43)