New != Faster

[Chris]

On 04/06/07, Kris Kennaway <kris at obsecurity.org> wrote:
> On Mon, Jun 04, 2007 at 08:54:50PM +0100, Chris wrote:
> > On 04/06/07, Colin Percival <cperciva at freebsd.org> wrote:
> > >Tim Daneliuk wrote:
> > >> Old   2 PIII @600Mhz           768K    26M/sec    4.11-stable/SMP
> > >> 50-60 min
> > >> New   Pent D (2 core)@3.2GHz   2G     50M/sec    6.2-stable/SMP
> > >> 40-50 min
> > >> Fast  2 Xeon @3GHz             3G    130M/sec    4.11-stable/SMP
> > >> 8 min
> > >>
> > >> Is the difference in speed
> > >> attributable to 4.11 being faster than 6.2?
> > >
> > >Close.  The difference in speed is due to the compiler in 4.11 being
> > >faster than the compiler in 6.2.  FreeBSD uses the gcc compiler, and
> > >between FreeBSD 4.11 and FreeBSD 6.2 that has been upgraded from 2.9
> > >to 3.4.  The general trend each time gcc is upgraded is that it takes
> > >2x longer to compile code, but produces code which is 5% faster (as a
> > >result of "working harder" to find optimizations).
> > >
> > >FreeBSD 6.2 is faster than FreeBSD 4.11 for almost everything except
> > >compiling itself. :-)
> > >
> > >Colin Percival
> > >
> > >_______________________________________________
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> > >
> >
> > What about all the following observations?
> >
> > slower disk performance especially under QUOTA.
>
> s/especially//, unless you have further evidence I don't know about.
>
> > both of these have been confirmed numerous times by different people
> > so sweeping them under the carpet and saying they simply not true
> > would be wrong.
>
> My detailed measurements of disk performance and those of others I am
> aware of contradicts your claim: 6.x equals or outperforms 4.x on disk
> I/O (depends on driver) and filesystem I/O.  The only true part of it
> is the "under QUOTA" part, which as you know from past discussions, is
> still under Giant in 6.x.  As you also know, there is a patch to
> address this which is awaiting user testing.  Have you tested it yet?
>
> Kris
>
Having some hardware coming this week when thats all setup I will have
a box available for testing patches.

Chris