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Date: Wed, 27 Feb 2013 15:58:34 -0700 (MST)
From: Warren Block <wblock@wonkity.com>
To: Frederico Costa <fredports@mufley.com>
Subject: Re: Performance Related Question
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 (wonkity.com [127.0.0.1]); Wed, 27 Feb 2013 15:58:34 -0700 (MST)
Cc: Michael Ross <gmx@ross.cx>, freebsd-questions@freebsd.org
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On Wed, 27 Feb 2013, Frederico Costa wrote:

> On 2013-02-27 22:27, Michael Ross wrote:
>> If I read you right, you didn't ``make -jX buildworld'',
>> with X being the number of processes to spawn,
>> so you used just one core on either machine.
>> 
>> Buildworld does a lot of I/O, so disk speed is relevant.
>
> Yes, i just made "make buildworld".
>
> So i should use make -j2 on the S1(dual core) and -j4 on S2 (2xdualcore)?
>
> And it also makes sense what you say about the I/O.

It really depends on the system.  On my dual-core systems, I use 
devel/ccache and found that -j8 gave the best performance.