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Inconsistent "Out-of-memory" Errors
Posted 24 giu 2011, 06:53 GMT-4 Version 3.5a 2 Replies
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Does anyone know why COMSOL 3.5 will not work everytime you run the same simulation on the same PC, but on different days? I've run a simple stress-strain simulation on a 1mm x 1mm x 1um diaphragm with an applied force in the z-direction. It worked the first time I ran it. I try to run it again this morning and I keep getting an out-of-memory error. When I change the coarseness of the mesh I still get an out-of-memory error just further along in the simulation process. The PC I'm using has a 3.2 GHz quad core processor and 4GB of memory, although it's a 32-bit system so Windows is only allocating 3.25 GB. This system should be more than sufficient to run such a simple simulation though. I had the mesh set as extremely coarse and was still getting the error. I'm getting the same issues with my laptop, which is a less powerful computer, but I've run similar simulations in the past on it and now it doesn't seem to want to run them anymore. It's become hit or miss whether COMSOL will actually execute the simulations or not.
2 Replies Last Post 26 giu 2011, 19:20 GMT-4
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Posted:
1 decade ago
Update: I got the simulations to work, but had to change the dimensions and use Client/Server mode for it to work. I reduced the dimensions to 500um x 500um x 1um diaphragm with the mesh set to extremely coarse for the simulation to work. That seems extreme for such a small diaphragm and simple stress-strain simulation. I don't know how COMSOL is using the memory, but it can't be utilizing it correctly. 3.25 GB physical memory, 4.25 GB vitual memory, plus whatever it offloads during operation in Client/Server mode should be able to do much more complex simulations than this, but it's not. I just need this to compare diaphragm thicknesses and some additional geometries for a report I'm working on so this should work.
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Posted:
1 decade ago
Are you using a swept mesh? If not, the element size (and therefore the required memory) will be dictated by the thickness of your diaphragm, so you can expect to run out of memory even at the extremely coarse setting if you don't use a swept mesh.
With that said, I still wouldn't recommend using a 32-bit OS for CAE.You can get a 64-bit machine with 16GB of RAM for around 1000 bucks these days.
With that said, I still wouldn't recommend using a 32-bit OS for CAE.You can get a 64-bit machine with 16GB of RAM for around 1000 bucks these days.