I'm running COMSOL simulations in a 64GB RAM workstation. So far I have been using the default settings. However recently I have noticed that when I have a much finer mesh, computation time is significantly larger. But the memory allocation for comsol, (at bottom of the window) remains around 2GB or something. How do I check the default memory allocation for comsol? How can I alter this for better memory utilization for comsol?
Thanks.
Hi,
Someone find the solution? I'm running COMSOL simulation in workstation with Intel Core i7- IV generation, 3.7 Ghz, 64GB RAM, 64 bit operating system and windows 8 but that is not enough to speed up the process. I'm only mixing a water with turbulent model k-e for 60 segundos and comsol ran for 10 days! I think it's so much time for doing that process! Comsol use all the memory for doing the process, How can i allocate the memory? can you give me some recommendation? sorry for my english! thanks!
Waranatha.
What kind of computer (operating system) are you running on (Windows, Mac, Linux, something else)?
Hi there. I do not think you can alter the memory allocation, but... may I know which version of COMSOL you are working with?
In the mean time, could you not try solving your simulations in stages, i.e., one/two physics at a time, and using the stored solution to obtain the multiphysics solution?
Generally speaking increasing the RAM does not speed up your calculations, it is the processor performance which has more say in it.
Hi,
Someone find the solution? I'm running COMSOL simulation in workstation with Intel Core i7- IV generation, 3.7 Ghz, 64GB RAM, 64 bit operating system and windows 8 but that is not enough to speed up the process. I'm only mixing a water with turbulent model k-e for 60 segundos and comsol ran for 10 days! I think it's so much time for doing that process! Comsol use all the memory for doing the process, How can i allocate the memory? can you give me some recommendation? sorry for my english! thanks!
COMSOL uses all your processors/threads by default with 64 bit system if it needs. However, if you want to check you can verify in File>Preferences>Multicore>Number of Processors. I don't think you have to worry about COMSOL not utilizing all your computational power of the desktop/laptop.
Dear Waranatha,
It seems that you are using a direct solver (PARDISO or MUMPS) and that it is switching to out-of-core settings when you are refining the mesh because you do not have enough RAM memory. In out- of-core the solvers stores part of the stiffness matrix in the hard drives/SSDs and thus the performance drops abruptly (HDs are tremendously slow in comparison to RAM memory). If you need to solve a model that cannot fit in your RAM I would recommend you to explore the iterative solvers (GMRES+Multigrid for example).
Kind regards,
Julian
In the settings for the direct solvers you can deselect out of core. I Always do this and this really speeds up the process. I use MUMPS for max 500000 DOF. And PARDISO when running larger models. PARADISO is more ram efficient.
For really large models I have a ssd setup as ram overflowing this is really slow but a budget solution.
For cpu optimisation I run batch sweep this gives a better utilisation steadily 70 to 90 %
- Badges
- Science topic