cosmomc: (optimal) number of chains in parallel ?

Use of Healpix, camb, CLASS, cosmomc, compilers, etc.
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Kanhaiya Pandey
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Joined: September 14 2015
Affiliation: IIAP, Bangalore, India.

cosmomc: (optimal) number of chains in parallel ?

Post by Kanhaiya Pandey » September 14 2015

Does the cosmomc run time reduce if I run a large number of (let us say 64 or 128) chains in parallel? Is there any optimal number for how many parallel chains should be used? What are the factors to take into account to decide on this number.

Antony Lewis
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Joined: September 23 2004
Affiliation: University of Sussex
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Re: cosmomc: (optimal) number of chains in parallel ?

Post by Antony Lewis » September 14 2015

I would usually use 4-8 chains, using any more than that is almost certainly wasting CPU time (having more chains doesn't make individual chains converge significantly faster).

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