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Tingguang Ma September 18, 2000 14:39

memory management!
Hi, I have a memory problem with Large Eddy Simulation. I have a Fortran code originally developed on Unix platform. My version is Windows-based and Digital Fortran with PC. My PC is Pentium 700Hz with 384M memory. But it could not run a 40x40x100 gridsize simulation. Someone told me that there is a memory orginizer which can help me free the memory taken by Windows. I wonder if anyone can help me to find the software. It must be a small one. Thanks for your kind help!


Sebastien Perron September 19, 2000 06:08

Re: memory management!
1) I recently worked on a project involving high-memory cost.

2) The people who I was working with had their project on windowsNT. I was working with unix (solaris, linux and freebsd)

3) they had a problem with memory management and windowsnt, windowsnt woulnd't even execute the problem If the main matrix (about 15750*15750 entries, double precision) was bigger than the above dimension. Even though they had enough memory on board (2.6gig). Do the calculation, about 400meg were waisted by NT, who knows why.

4) If your program doest'nt use graphics, May I suggest you switching to linux on you PC. Memory management is much better on unix system than windows. Try Mandrake, in less than an hour it will be up and running.

nuray kayakol October 21, 2000 12:21

Re: memory management!
I advice you check your Digital Fortran code generation settings. As far as I know Digital added many valuable options to fortran user with Digital Fortran 6.0 after microsoft developer studio (Fortan Powerstation 5.0). There are some options to optimize or vectorize your code or some guides to write an efficient code. For example you can use 1D index for 3D vector operations. This is usually what some softwares do for running codes efficiently.

Tingguang Ma October 25, 2000 08:35

Re: memory management!
I solved my problem by just increasing the stack numbers in the compiling option in Digital Fortran. I am new with this version. Thanks! Tingguang

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