Maximum array size in Fortran 90

[clergy1122]

Hi Guys,

I wrote a code that part of it looks like:

integer: imax
parameter(imax=4000)
double precision,dimension(imax,imax): clst,Nver.

When I used imax=500, it worked so well, but with imax=4000, it gives error like this:

libc detected *** malloc(): memory corruption: 0x1c109cb8 ***
forrtl: error (76): IOT trap signal
/var/spool/pbs/mom_priv/jobs/72248.totor.SC: line 6: 31794 Aborted .

I am using Intel fortran compiler. My friends say it could be due to the array size, but I want to seek your advice as me and my friends are all learners.
Does Fortran has a maximum array size?

Thanks in anticipation.

 

[xwb]

Your friend is right. Check your compiler documentation.

A way of looking at it is

4000*4000*8
=128000000
= appx 128Mb

That is how much space you're using.

a) Could you make it a real array instead of double precision? That would reduce it to 64Mb

b) Do you really need an array that size? For data input, that would mean you have to input 16 million numbers. Is that practical?

c) Is it a sparse array (i.e. most of it is zero). If so, there are other techniques for handling sparse arrays.