Dave -
I think your analysis is basically correct in all respects. - Bob
----- Original Message -----
From: "David A. Case" <case.scripps.edu>
To: <amber-developers.scripps.edu>
Sent: Tuesday, April 27, 2004 6:34 PM
Subject: Re: amber-developers: UNC JAC benchmark?
> On Tue, Apr 27, 2004, Carlos Simmerling wrote:
>
> > is that JAC timing of 202ps/day for single 3.2ghz Xeon at UNC/duke
> > correct? (on the benchmarks page)
> >
> > if yes, then why is the "fix" number for UNC/duke much closer to the
bohr
> > data?
> >
>
>
> Just to make sure you are looking at the correct ratios:
>
> For clock speeds, unc/bohr = 3.2/2.4 = 1.33
>
> for JAC (2 cpu) unc/bohr = 330/165 = 2.0
>
> for fix (2 cpu) unc/bohr = 120/78 = 1.54
>
> My guess (assuming no typos....) is that the new 3.2 GHz PIV have a much
> bigger L2 cache, which is why both ratios are better than the ratio of
> clock speeds per se. For the smaller JAC problem, the "extra" cache on
the
> newer machine is a real win, but for the bigger system, both processors
> blow cache more often, and the "win" for the unc system is not so great.
>
> Note also that the relative speeds of altix vs. unc are reasonably
similar
> for both the jac and fix benchmarks.
>
> And, according to Bob, going to ifc8 will make the new 3.2 Xeon chips
look
> even better than the ifc7 numbers shown on the benchmark page.
>
> [Now, you can wait for the correct answers from others on this list....]
>
> ...dac
>
> --
>
> ==================================================================
> David A. Case | e-mail: case.scripps.edu
> Dept. of Molecular Biology, TPC15 | fax: +1-858-784-8896
> The Scripps Research Institute | phone: +1-858-784-9768
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> La Jolla CA 92037 USA | http://www.scripps.edu/case
> ==================================================================
>
Received on Wed Apr 05 2006 - 23:50:03 PDT
