# PackageCompiler: Do optimisation flags influence the produced sysimages?

**URL:** <https://discourse.julialang.org/t/packagecompiler-do-optimisation-flags-influence-the-produced-sysimages/47338>\
**Category:** Performance\
**Tags:** package-compiler, sysimage\
**Created:** [September 26, 2020, 9:07pm UTC](https://discourse.julialang.org/t/packagecompiler-do-optimisation-flags-influence-the-produced-sysimages/47338 "2020-09-26T21:07:34Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![SteffenPL](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/steffenpl/32/206270_2.png) [@SteffenPL](https://discourse.julialang.org/u/SteffenPL)\
**Post date:** [September 26, 2020, 9:07pm UTC](https://discourse.julialang.org/t/packagecompiler-do-optimisation-flags-influence-the-produced-sysimages/47338/1 "2020-09-26T21:07:34Z")

</div>

Is there a difference between  
`julia -O3 -e "import PackageCompiler; PackageCompiler.create_sysimage(...)"`  
vs  
`julia -e "import PackageCompiler; PackageCompiler.create_sysimage(...)"`?  
Are the produced sysimages the same or is the first variant producing more optimised sysimages?