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Date:      Wed, 26 Nov 2008 09:43:14 +0100
From:      Alexander Leidinger <Alexander@Leidinger.net>
To:        Ivan Voras <ivoras@freebsd.org>
Cc:        Adrian Chadd <adrian@freebsd.org>, freebsd-performance@freebsd.org
Subject:   Re: FreeBSD 7.1 BETA 2 vs Opensolaris vs Ubuntu performance
Message-ID:  <20081126094314.119834gt66jv0g00@webmail.leidinger.net>
In-Reply-To: <9bbcef730811251246nf39e825s95a25ae394948e06@mail.gmail.com>
References:  <DE23C2B055DA4BC683BDCAA95FF7B736@multiplay.co.uk> <gggmbb$un6$1@ger.gmane.org> <20081125173657.GA50429@freebsd.org> <ggher5$qq0$2@ger.gmane.org> <d763ac660811251202n5dafbbl896ad194435436a0@mail.gmail.com> <9bbcef730811251246nf39e825s95a25ae394948e06@mail.gmail.com>

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Quoting Ivan Voras <ivoras@freebsd.org> (from Tue, 25 Nov 2008 =20
21:46:35 +0100):

> 2008/11/25 Adrian Chadd <adrian@freebsd.org>:
>> 2008/11/25 Ivan Voras <ivoras@freebsd.org>:
>>
>>>> I believe most of the synthetic numbers (mp3 encoding etc.) difference
>>>> comes from the different version of gcc the different OS uses...
>>>
>>> You're very likely right. Ubuntu 8.10 has gcc 4.3.x - it could make for
>>> the small difference in gzip and 7z compression performance.
>>
>> Well, that should be a reasonably easy thing to test and feed back to
>> the author.
>
> OTOH if the goal is to measure "operating system" performance, this

If you want to test OS performance and use Java programs in there to =20
do so, you would use the same Java version, wouldn't you? They didn't.

If you want to run some high performance java software and you want to =20
know on which OS it performs best, you would test the same Java =20
version on the OS' in question (or at least you should do that, to not =20
compare apples and oranges).

If you want to run number crunching software, you are interested in =20
high computing throughput of your app, so you use a compiler which =20
performs best for your code in question (which would mean probably the =20
Intel compiler or the Portland compiler on Linux, maybe the Sun =20
compiler on Solaris, and probably gcc on FreeBSD). You also want to =20
optimize the code for your CPU (it makes a difference if you do =20
floating point calculations and are allowed to use the SSEx or =20
whatever instructions), and not some generic settings the OS comes with.

The "benchmark" presented there is flawed in a lot of ways. No =20
descrition what they really want to benchmark, no description what =20
each subtest benchmarks (e.g. lame is performing on one CPU and =20
occasionally performs IO, what does this benchmark mean? That your =20
multi-CPU system is mostly idle and can be used to browse the net =20
without that you notice any impact). Only absolute numbers and no =20
relative performance comparision (percentage of difference). =20
Inconsistent starting point (not the same compiler, not the same java =20
version, ...) in case you want to promote an OS for specialized tasks =20
(there are comments which tell FreeBSD would be good for raytracing, =20
as the corresponding subtest was the fastest on FreeBSD), and so on.

Did I overlook some part where they tell how they test? Do they =20
calculate the average of several runs?

> must also include the compiler, libraries and all. (for example, what
> does Solaris default to nowadays? I think it ships with gcc but not as
> default). The hold on gcc 4.3 in FreeBSD is, after all, political
> (licencing).

Users most of the time don't care what the reasons are, they use what =20
is there and complain or switch if it works better somewhere else. =20
People which care about compute intense stuff, will install their =20
preferred compiler anyway.

Bye,
Alexander.

--=20
So so is good, very good, very excellent good:
and yet it is not; it is but so so.
=09=09-- William Shakespeare, "As You Like It"

http://www.Leidinger.net    Alexander @ Leidinger.net: PGP ID =3D B0063FE7
http://www.FreeBSD.org       netchild @ FreeBSD.org  : PGP ID =3D 72077137



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