[gmx-users] same simulation, different results

[David van der Spoel]

Stéphane Téletchéa wrote:
> Jim Fonseca a écrit :
>> Thanks a lot--that was it.
>>
>> On May 15, 2007, at 12:42 PM, David van der Spoel wrote:
>>
> 
> Furthermore for a real test case, i would use a monoprocessor run since 
> nic interfaces and smp can introduces little artifacts (roundoffs) 
> leading to divergence after a few ps, as reported by Robert Duke on the 
> AMBER mailing list a while ago.
> 
> Cheers,
> Stéphane
> 
That sounds unlikely. I think the simulation is deterministic even in 
parallel. Gromacs implements its own random number generator (e.g. for 
REMD) and hence everything should be reproducible. If not it is a bug.

-- 
David.
________________________________________________________________________
David van der Spoel, PhD, Assoc. Prof., Molecular Biophysics group,
Dept. of Cell and Molecular Biology, Uppsala University.
Husargatan 3, Box 596,  	75124 Uppsala, Sweden
phone:	46 18 471 4205		fax: 46 18 511 755
spoel at xray.bmc.uu.se	spoel at gromacs.org   http://folding.bmc.uu.se
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