Re: NetBSD vs FreeBSD

["Ian D. Leroux" <idleroux%fastmail.fm@localhost>]

On Tue, 02 Aug 2011 21:12 +0200, "Daniel Carrera" <dcarrera%gmail.com@localhost>
wrote:
> Hello,
%> Still curious about the differences between NetBSD and FreeBSD, so 
> Googling around I came across this post:
> 
> http://mail-index.netbsd.org/port-i386/2009/02/09/msg001189.html
> 
> The poster says that NetBSD is faster.

Such sweeping performance claims are nearly always silly.

> Does anyone here agree/disagree? I ask because I thought FreeBSD was 
> supposed to be the speedy one. In general I don't care much about speed, 
> but some times I run simulations on my computer. I have no idea if any 
> BSD or Linux is particularly good for that.

Historically, the received wisdom was that FreeBSD was more heavily and
effectively optimised for i386 performance (especially server
performance) than
NetBSD.  FreeBSD put a lot of effort into SMP in the early-mid 2000s
which
initially did bad things for single-core performance (the infamous 5.x
series,
now long behind them) but gave them a head start on effective use of
multi-core processors.  NetBSD put a lot of work into this area more
recently
and has mostly caught up.  A very impressive series of presentations
came
out along with the NetBSD-5 release to publicise this fact, showing
NetBSD
outrunning FreeBSD on a number of standard benchmarks; I'll bet the post
you link to was about them.  They laid to rest the idea that NetBSD was
generally slower, but I don't think they prove that NetBSD is generally
faster. 
Even if it was at the time the benchmarks were run, both systems are
constantly evolving.

Remember that many of the speed comparisons you see online are for
servers, or benchmarks that try to approximate server workloads.  The
requirements for number-crunching simulations are likely to be quite
different, making those benchmarks more than usually useless.  For
instance,
in the limit that your simulations are CPU-bound the OS should make no
difference at all.  In reality, differences in memory management and
disk i/o
will probably have an influence, but it's very difficult to guess how
much without
a careful benchmark of the workload you care about.

In practise, proper configuration of your system is likely to make a
much
bigger difference to performance than choice of OS.  That, in turn,
implies that
you should look for good documentation and a community of people using
the
OS for purposes similar to your own, so that you can learn how to get
the best
out of it.

Ian Leroux