memory limit opengrads windows XP

[Arlindo da Silva]

On Mon, Nov 16, 2009 at 8:32 AM, Elbers, Jan <Jan.Elbers at wur.nl> wrote:

>  Dear Mr. Da Silva,
>
>

Please send messages to the gradsusr list...


> When defining large arrays i seem to run into a memory limitation of
> Opengrads 2.0.a7.oga.3.
> Could you please let me know if there is a limit on one individial array or
> on all defined arrays together?
>
> I am using ECWMF re-analisis data for the northern hemispere resulting in
> arrays of 181 x 720 x 488 grid cells (X x Y x T). At the point where it goes
> wrong opengrads.exe has allocated about 1 Gb of memory on my PC which has 2
> Gb of RAM.
>
>

One 3D array of this size consumes around 500Mb of memory as GrADS v2 uses
double precision (8 bytes) to store each gridcell. Depending on your format,
it could be caching some of the I/O, which results in even more memory
usage. Your may stretching the limits of your hardware.

Now, GrADS v1.x uses 4 bytes to store each grid cell resulting in about half
the memory usage of GrADS v2.  Unless you need GrADS v2 specific features,
the Win32 Superpack v1.9-rc1 is probably the best option for dealing with
such large arrays on your hardware:

   https://sourceforge.net/projects/opengrads/files/grads1-windows/1.9.0-2/

(I just realized that we never released v1.10.r2.oga for Windows...)

    Arlindo



--
Arlindo da Silva
dasilva at alum.mit.edu
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