[MITgcm-support] BLOCKING_EXCHANGES slowdown when using pkg/ptracers on Columbia

[Constantinos Evangelinos]

On Thursday 11 March 2010 05:52:23 am Martin Losch wrote:

> I observed a huge slowdown with ptracers as well, the solution was to copy
>  ptracers into a new 5D-array where the 3rd index (k) is nPtracer*Nr long,

You mean 3D I take it.

>  and then use one exchange for that (and I think I had to hack the
>  corresponding exchange routine to have it allow such large arrays). Can
>  provide code if required.

Since more than one person has this problem it might be a good time to add the 
code (as an IFDEF) in the main code.

Constantinos
-- 
Dr. Constantinos Evangelinos
Department of Earth, Atmospheric and Planetary Sciences
Massachusetts Institute of Technology