# What NGX\_POOL\_ALIGNMENT is used for?

**URL:** <https://www.ruby-forum.com/t/what-ngx-pool-alignment-is-used-for/209032>\
**Category:** NGINX\
**Created:** [July 3, 2011, 5:02pm UTC](https://www.ruby-forum.com/t/what-ngx-pool-alignment-is-used-for/209032 "2011-07-03T17:02:32Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![luislavena](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/0ea827/32.png) [@luislavena](https://www.ruby-forum.com/u/luislavena)\
**Post date:** [July 3, 2011, 5:02pm UTC](https://www.ruby-forum.com/t/what-ngx-pool-alignment-is-used-for/209032/1 "2011-07-03T17:02:32Z")

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Hi!  
As far as i know, malloc return pointer aligned for using with standart  
data  
types (int, long, struct, etc… usually 8 bytes).  
Why is NGX\_POOL\_ALIGNMENT = 16 ? Why is that ? For 64-bit systems ?  
I’m very interested in nginx internals, i can learn a lot from it.  
PS: discussion at stackoverflow, people also don’t know the reason of  
number  
16.

> <https://stackoverflow.com/questions/6410609/when-do-we-need-to-use-posix-memalign-instead-of-malloc>

Please help.