CPU Choices

[Craig Tierney]

Thanks for the pointers.  They are very interesting reading.
However, the conclusions are:

1) You need a good compiler to get the most out of your hardware.
2) The only good benchmark is your own code.

I care about Fortran 77 and 90 performance, not raytracers and
modelling packages.  My results show that the Dual Xeon 1.7 Ghz
is 30% faster than the Dual Athlon 1.2 Ghz for the 3 codes I ran when
compiled with the Intel Fortran compiler for Linux.  I have some more to 
do, but it seems that for my codes the Xeon processor is best.

Craig



On Sat, Sep 22, 2001 at 11:13:23AM -0700, Ron Chen wrote:
> Some interesting articles:
> 
> Floating-Point Compiler Performance Analysis 
> ============================================
> http://www.aceshardware.com/Spades/read.php?article_id=40000189
> 
> Workstation Battle Royale
> =========================
> (The Top Dual Xeon Workstations and the Dual Athlon
> MP)
> http://www.aceshardware.com/Spades/read.php?article_id=45000195
> 
>  -Ron
> 
> --- Craig Tierney <ctierney at hpti.com> wrote:
> > On Fri, Sep 21, 2001 at 10:35:25AM -0000,
> > n.gregory at garageflowers.co.uk wrote:
> > > (sorry if this gets posted twice)
> > > Hello,
> > > I am doing some research into the configuration of
> > a 32 1U node Beowulf cluster 
> > > and have a question regarding CPU configuration.
> > > 
> > > The current choice is between Intel P4s as
> > Itaniums seem a little bleeding edge at 
> > > the moment, or the latest AMD chips.
> > > 
> > > AMD seem to be getting a impressive performance
> > for the price, but I?m a little 
> > > concerned about the lack of mature multiprocessor
> > chipsets and their heat issues.
> > 
> > Have you run your code on an AMD and P4?  Alot of
> > the published
> > reports show AMD as faster, but mainly for codes
> > that I don't care
> > about and that havenot been recompiled.
> > 
> > For the codes I am interested in a dual P4 1.7 Ghz
> > is 30% faster
> > than a dual Athlon 1.2 Ghz when using the Intel
> > compiler for Linux.
> > SSE support is better in the Intel compiler than the
> > Portland Group 
> > Compiler.  I didn't seem much improvement using
> > Portland Group and SSE
> > than non-SSE.  With the Portland Group compiler the
> > two systems perform
> > similiary (within 5%).
> > 
> > You are going to spend probably 150K (or more) on
> > hardware, but aren't
> > willing to shell out $1k (or less) for commercial
> > compilers?  For the 
> > Portland Group compiler, you only need to buy a
> > license for the nodes you
> > are going to compile on (Front ends).  I do not know
> > about the
> > Intel compiler, but I hope it is the same.  Anyone
> > know?
> > 
> > 
> > Craig
> > 
> > > 
> > > Intel on the other-hand have the MP chipsets but
> > seem to be falling down with 
> > > current lack of (non-commercial ) complier that
> > support MMX and SSE, and the 
> > > whole issue of Rambus Vs DDR memory.
> > > 
> > > I would be grateful for any insight into a choice
> > of CPU and its configuration in 
> > > terms of price/performance/expandability, or any
> > other factor I should be 
> > > considering.
> > > 
> > > Thanks
> > > Nick
> > > 
> > > _______________________________________________
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> > 
> > -- 
> > Craig Tierney (ctierney at hpti.com)
> > 
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-- 
Craig Tierney (ctierney at hpti.com)