Error allocating memory

Has anybody had such problem ? I have exactly the same problem (as below) my first action was Prepomax forum but admin said that this maight be a calculix problem . Can anybody help ?

Hi Michal,

I can see there are 1.8M nodes on that file. It is a big number.
How much Ram do you have on your computer?
Which solver are you using?

Based on the discussion on PrePoMax forum, I’m afraid that it won’t work until you reduce the density of that mesh or switch to shell elements.

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probably you have to use the i8 version of ccx (and then see if you have enough memory to run to completion) for that problem size.

I have model with similar problem ca 3,2 million of elements , I have ram 64 GB and I use pardiso

where can I find i8 version of ccx what does mean this option
best regards

check out this thread, I think I got it from here…but not sure (mine is v2.19 for windows)…CalculiX i8 and mingw - #7 by jbr

anyway 64GB of ram should be enough for about 2 Million equations (dofs) according to the manual, so keep it in mind.

from the installation guide :

USING CALCULIX with 8 byte per integer

This may be necessary for really big models. Right now, there is a file
Makefile_i8 showing you how it works. The integers in the FORTRAN files must
be compiled with the option -fdefault-integer-8 (for the GNU compiler). This
tells the compiler to consider all integers in the FORTRAN files as
8-byte integers. For the C-files, the flag -DLONGLONG must be added to the
CFLAGS. Right now, the CalculiX distribution assumes that you also generate
a integer8 version of ARPACK (use the above FORTRAN flag) and an
8 version of PARDISO (of course only if you use any if these, i.e.
if you have the flags -DPARDISO and -DARPACK in your Makefile). The
SPOOLES distribution, however, is assumed to be an integer 4, since it
is not known that an integer
8 version of SPOOLES has already been made.

ccx 2.19 included both static and dynamic i8 versions already compiled.
Not sure where to download it now. Mine was probably from CalculiX main page.

CalculiX Version 2.19 i8, Copyright(C) 1998-2021 Guido Dhondt
CalculiX comes with ABSOLUTELY NO WARRANTY. This is free
software, and you are welcome to redistribute it under
certain conditions, see gpl.htm


Could anybody prepare complete kit of solvers for PPM/ Calculix for Windows to solve large problems . So far I have used several variants of 2.19 and 2.20 for windows os without success . I stiil can not resolve model with 4,5 milion of nodes even using Iterative solvers (error in u_realloc: allallocating memory) I have also searched in PREPOMAX forum. I have used dynamici8.exe but it also doesn’t work
best regards