[Beowulf] array shape difference

[Michael H. Frese]

At 06:43 PM 11/10/2009, Larry Stewart wrote:


>On Tue, Nov 10, 2009 at 8:30 PM, amjad ali 
><<mailto:amjad11 at gmail.com>amjad11 at gmail.com> wrote:
>HI,
>
>suppose we have four arrays with same number of elements say 60000., 
>but different dimensions like:
>
>array1(1:60000)
>array2(1:2, 1:30000)
>array3(1:2, 1:300, 1:100)
>array4(1:4, 1:15, 1:10,  1:100)
>
>
>Does each of these arrays in fortran will occupy same amount of memory?
>
>For sending/receiving each of these, Does MPI has the same (or 
>nearly same) overhead? or any significantly different overhead is 
>involved in handling each of these arrays (by MPI)?
>
>They should take the same amount of space and have nearly identical 
>transfer times with MPI.
>(If you send the whole thing)
>
>-L

Those four array descriptors can all apply to exactly the same space, 
via an 'equivalence' statement.  They are all laid out in memory just 
like array1.

Thus, they can each be transmitted by exactly the same MPI send.


Mike
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