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Date: Fri, 12 Sep 2014 18:08:09 -0600 (MDT)
From: Warren Block <wblock@wonkity.com>
To: Andrew Berg <aberg010@my.hennepintech.edu>
Subject: Re: Request Validation of my Experience in buildworld
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On Fri, 12 Sep 2014, Andrew Berg wrote:

> On 2014.09.12 15:16, Dave Babb wrote:
>> The WRKDIRPREFIX (from a answer I received in this mailing list), is so
>> that my ports and kernel are built in ram and not to the SSD until they
>> are complete. I have /usr/obj mounted in tmpfs.....I have 32Gb of
>> ram....of which I only used 7% of tmpfs during any of the experiences
>> below......
> ...
>> Another dramatic drop in resources and another increase in performance.
>>
>> This experience was had across a desktop, and repeated on a ASUS laptop.
>>
>> Is this type of improvement typical?
> Yes. Putting your WRKDIR in RAM eliminates the biggest bottleneck and puts
> almost everything on the CPU, which is quite fast. You can use ccache to cache
> objects and make future builds even faster by not rebuilding anything
> unnecessarily.

ccache does not help much or at all with Clang.  Using NO_CLEAN can be 
even more effective, as long as /usr/obj is kept around.