[gmx-users] GROMACS compilation problem on IBM AIX

Erik Lindahl lindahl at stanford.edu
Mon Feb 3 18:56:22 CET 2003

On Monday, Feb 3, 2003, at 09:43 US/Pacific, David van der Spoel wrote:

> On Mon, 2003-02-03 at 15:16, Gerrit Groenhof wrote:
>> Hi Jithesh,
>> I am not sure, but from your benchmark it seems gromacs is not
>> compiled properly. I had the same problem on an IBM SP3 (4?). changing
>> the optimization from O3 to O2 did the trick. What also works is to
>> change from the IBM xlc compiler to the gnu gcc compiler.
> And it is also very important to check that all libraries are compiled
> with the same options (for hardware specifics: the processor type). If
> you compile part for power3 (e.g. fftw) and part for power4 (gromacs)
> your simulations will die.
> Check an option in fftw compilation, it could be that they default for
> the wrong architecture.,

Yeah, but I think it will just default to pwr2 which should be fine 
(although not as fast).

There might indeed be a problem with the IBM compilers; if anybody can 
access to a power4 system I'll have a go at debugging it.



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