#72 Parallel Simulation

[Carlos Martin Cañal]

Hi h_vogt,
I would like to ask for the possibility of doing simulation in parallel using ngspice.
Regards,
Carlos

[Holger Vogt]

Please define what you mean by "parallel simulation".

[Carlos Martin Cañal]

Hi again,
what I want to say with parallel simulation" is if there is a way to cut
the circuit in some parts and simulate each part in a ngspice process.
Carlos

[Holger Vogt]

Some time ago I have made a small study on parallel simulation with ngspice shared libraries, see https://ngspice.sourceforge.io/parallel.html .

This would require a lot of work (concept and programming of a calling program). Concepts for circuit patitioning and simulation synchronization would be the major tasks to get this up and running..

[Carlos Martin Cañal]

Hi,
i am trying your code, but in this moment I am working in Linux and I have
some problems to compile the project because some Windows functions are used
Could you change the code to compile in linux?
Thanks in advance
Carlos

[Holger Vogt]

Replace sharedngspice.h with the current version (https://sourceforge.net/p/ngspice/ngspice/ci/master/tree/src/include/ngspice/sharedspice.h)

Compile shared ngspice (see script compile_linux_shared.sh)

Copy libngspice.so to libngspice2.so and libngspice3.so

Go to the dir containing main.c.

Try running
gcc main.c -m64 -Wall -s -lpthread -ldl -o ./bin/Release/ng_sync

[Carlos Martin Cañal]

Ok!, I've got to compile and execute it. I don't have to copy any library
.so to compile.
Thanks
Carlos

[Holger Vogt]

But you will need libngspice.so to run it!

Please don't reply with copying the old text contents. If you look at https://sourceforge.net/p/ngspice/support-requests/72/, that is annoying.

[Francesco Lannutti]

Hi all,
parallelizing in this way is called FastSPICE, while NGSPICE is a pure SPICE simulator.

Thank you,
Fra

[Carlos Martin Cañal]

Regarding to copy text, I answer to you by gmail, and the text is copied automatically.
And I could run the program because previously, I installed the shared library.
So the problem is fixed.
Thanks,
Carlos

[Holger Vogt]

Regarding to copy text, I answer to you by gmail, and the text is copied automatically.

Then please delete it manually before sending a reply.

I would be interested in hearing about your new insights when dealing with parallel simulation.

[Carlos Martin Cañal]

Ok, I will take it into account .
Regarding the parallel simulation, I will develop it slowly because I can't dedicate it much time,
but I will inform you about my progress.
Carlos

[Carlos Martin Cañal]

One question, to show the .raw output file from simulation, what program could I use to show them?

[Holger Vogt]

Use ngspice, with the 'load' command.

[Carlos Martin Cañal]

Ok, now I have another problem: 'Can't open viewport for graphics'. I've revised the library and they are installed. I've installed using the 'compile_linux_dist.sh' script

[Carlos Martin Cañal]

Solved! I've reinstalled the ngspice

[Carlos Martin Cañal]

I've been thinking about in the parallel simulation, and I have a doubt, as you carried out the parallelization, you can send voltage or current, but not both. The idea would be to parallelize the solver, since each subpart of the whole circuit shares currents and voltages in the common nodes each other and they should be solved together. Your solution can be used in firstly stage of the design but no for more serious simulations. In this case, the solver should be parallelized.
Carlos

[Carlos Martin Cañal]

I was thinking about that, I found a library called MUMPS: MUltifrontal Massively Parallel sparse direct Solver, I dont't know if it is useful, but it could be taken a look to check it.
Regards,
Carlos