Hi John,
thanks for your answer.
ig=-1 will set some random seed number to create in turn a set of random
numbers for the the initial atom velocities.
Any other ig=x is setting the random seed number explicitely to the number
x from which initial velocities are then derived.
/ Oliver
2012/2/24 Cannon, John F. <CannonJ.health.missouri.edu>
> My understanding is that you use ig=-1 if you want a different random seed
> for velocities.
>
> John Cannon
> Genetics Program Chair and
> Associate Professor of
> Molecular Microbiology and Immunology
> University of Missouri
> 1 Hospital Drive
> Columbia, Missouri 65212
>
>
> -----Original Message-----
> From: Oliver Kuhn [mailto:oak.amber.googlemail.com]
> Sent: Friday, February 24, 2012 10:37 AM
> To: AMBER Mailing List
> Subject: [AMBER] same simulation using different random seeds on GPU
>
> Hi.
>
> I want to use differing initial random velocities for simulations running
> on GPU.
> That has always been working on CPU, but on the GPU I get exactly the same
> simulation.
>
> For example, input 1 is:
>
> production simulation (NPT) - 2 ns
> &cntrl
> ig=1,
> irest=0,ntx=1,
> nstlim=1000000,dt=0.002,
> temp0=300.0,ntt=1,tautp=1.0,
> ntc=2,ntf=2,
> cut=9,
> ntpr=500,ntwx=500,ntwv=0,ntwe=500,iwrap=1,
> ntb=2,ntp=1,pres0=1.0,taup=1.0,
> ntr=0
> /
>
> and another input has ig=41
> giving me same simulations!?
>
> As I googled, I found a comment from Ross that GPU uses different random
> number generators.
> I'm quite sure he does not mean also different syntax in using it.
> Has anyone experienced similar problem and can help me?
>
> Greets,
> Oliver
>
> --
> Oliver Kuhn, Department of Bioinformatics, Center for Medical
> Biotechnology, University of Duisburg-Essen, Universitätsstr. 1-5, 45141
> Essen, Germany phone +49 201 183-3121, oliver.kuhn.uni-due.de_______________________________________________
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>
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--
Oliver Kuhn, Department of Bioinformatics,
Center for Medical Biotechnology, University of Duisburg-Essen,
Universitätsstr. 1-5, 45141 Essen, Germany
phone +49 201 183-3121, oliver.kuhn.uni-due.de
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Received on Fri Feb 24 2012 - 09:00:03 PST
