# Performance issue with specifying random number generator

**URL:** <https://discourse.julialang.org/t/performance-issue-with-specifying-random-number-generator/1076>\
**Category:** Internals & Design\
**Created:** [December 20, 2016, 11:05pm UTC](https://discourse.julialang.org/t/performance-issue-with-specifying-random-number-generator/1076 "2016-12-20T23:05:59Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![ihnorton](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/ihnorton/32/26_2.png) [@ihnorton](https://discourse.julialang.org/u/ihnorton)\
**Post date:** [December 20, 2016, 11:16pm UTC](https://discourse.julialang.org/t/performance-issue-with-specifying-random-number-generator/1076/2 "2016-12-20T23:16:11Z")

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> [@danspielman](#):
>
> Exposing the name of the default RNG

Ref:

> <https://github.com/JuliaLang/julia/issues/18488>
>
> http://docs.julialang.org/en/latest/stdlib/numbers/?highlight=rand#Base.rand ref…ers to GLOBAL\_RNG, but the value is not exported.
> 
> My use case is I write a random number generator (specialized for my use), and the underlying AbstractRNG is passed in to the constructor, with GLOBAL\_RNG as the default value.
> 
> Shouldn't GLOBAL\_RNG be exported?

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