[gmx-users] Re: latest benchmarks (Itanium/Xeon/Opteron)

[Anton Feenstra]

Erik Lindahl wrote:
> Hi Anton,
> 
> You probably intended to submit this to the users list; gmx-users-admin 
> only goes to me :-)

Yup - apparently Mozilla mail outsmarted me here... ;-)

> The long answer, as always, is "it depends", but here's the short one:
> 
> Opteron:
> 
> If you compile in 32-bit mode you can use the current version of the SSE 
[...]
> machines. However, the 64-bit code will NOT be faster in most cases - 

> Itanium2: (NOT itanium1)
> 
> I have assembly loops that achieve 90+ percent of peak CPU 
[...]
> twice that of non-assembly loops compiled with the latest version of the 

OK, Thanks Erik for the prompt reply. Can I add the factor 2 to your quite
by David that "According to Erik Lindahl a 900 MHz Itanium is slightly faster
than a 3 GHz Xeon for gromacs (next version)", so that a 1.4GHz Itanium2 would
about three times the speed of a 3GHz Xeon?

Then remains the relative performance of Xeon versus Opteron. Any thoughts
on that anyone?

We're reviewing several hardware offers now, production simulations won't
start in the next few months, so I could assume the remaining hitches in the
assembly code and hardware specs are sorted out before then... ;-)


-- 
Groetjes,

Anton
  _____________ _______________________________________________________
|             |                                                       |
|  _   _  ___,| K. Anton Feenstra                                     |
| / \ / \'| | | Dept. of Pharmacochem. - Vrije Universiteit Amsterdam |
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