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Out of memory

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Hello,
I am modeling 3D Brain in comsol 3.5a (in acoustic and heat transfer transient). My geometry is a little complicated but my computer is powerful.
Windows 7 64bit, CPU: Intel(R) Core (TM)2 Duo E6750 @ 2.66 GHz and 8GB ram

I don't know how to do to eliminate out of memory error. I can just solve it with coarse mesh. Please tell me what to do.
Should I increase the CPU and ram of my computer? Or this error has nothing to do with my computer hardware.
And also I want to know can comsol support for example 16GB ram and CPUs like Corei7?

Thanks a lot. Any kindness help would be much appreciated.


With Best Regards,
Fatemeh Sharifi


3 Replies Last Post 2010年10月23日 GMT-4 07:14
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 2010年10月23日 GMT-4 04:58
Hi

COMSOL supports as much RAM as you manage to push into your HW, and 24CPU or more if you have anough cash to buy and power them. But usually its better to study your model and to see if there is not ways to reduce the memory consumption, as a large problem needs often a loooong time to solve and then is tedious to debug.

Check symmetries, solver settings (direct rapid but more ram versus iterative, longer solving but less ram) Do you need all dependent variables ? can yu turn off some frames ... It's all model dependent

--
Good luck
Ivar
Hi COMSOL supports as much RAM as you manage to push into your HW, and 24CPU or more if you have anough cash to buy and power them. But usually its better to study your model and to see if there is not ways to reduce the memory consumption, as a large problem needs often a loooong time to solve and then is tedious to debug. Check symmetries, solver settings (direct rapid but more ram versus iterative, longer solving but less ram) Do you need all dependent variables ? can yu turn off some frames ... It's all model dependent -- Good luck Ivar

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Posted: 1 decade ago 2010年10月23日 GMT-4 05:24
Thank you very much
I cannot use symmetry because I my model is not symmetric. I use Pardiso Out of core. I tried all of them and I assume this is the best solver, isn't it?
What do you mean by all dependent variable? When I launch comsol I just chose T and P to be my variables.
I don't know whether or not comsol add some more variable to it. If yes, please tell me how I can reduce these variables.

Can I somehow increase removing this error by increasing time duration of solving problems? (Like other softwares: Fluent and Ansys)

Thank you in advance,

With Best Regards,
Fatemeh Sharifi

Thank you very much I cannot use symmetry because I my model is not symmetric. I use Pardiso Out of core. I tried all of them and I assume this is the best solver, isn't it? What do you mean by all dependent variable? When I launch comsol I just chose T and P to be my variables. I don't know whether or not comsol add some more variable to it. If yes, please tell me how I can reduce these variables. Can I somehow increase removing this error by increasing time duration of solving problems? (Like other softwares: Fluent and Ansys) Thank you in advance, With Best Regards, Fatemeh Sharifi

Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 2010年10月23日 GMT-4 07:14
Hi

you seem to have checked the most evident. I do not know of any "time limit" in COMSOL that would not change your issue. It's mainly how to reduce the RAM demand, and to clean your PC from whatever else that is not required (on mine with 2Gb, the OS uses1.3 ! for nothing in fact, but most OS believe eveerything is for them and that nobody else could need any RAM ;)

--
Good luck
Ivar
Hi you seem to have checked the most evident. I do not know of any "time limit" in COMSOL that would not change your issue. It's mainly how to reduce the RAM demand, and to clean your PC from whatever else that is not required (on mine with 2Gb, the OS uses1.3 ! for nothing in fact, but most OS believe eveerything is for them and that nobody else could need any RAM ;) -- Good luck Ivar

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