Reno Genest
Ansys Employee


How much memory do you really need? You could use memory= and memory2= on the expression line (memory= is already set).


This should allow you to use less total memory for this problem.

Here is more information from our knowledge database:


"memory=" specifies the memory for the 1st core where decomposition is performed.
"memory2=" specifies memory for the 2nd and subsequent cores.  
If "memory2=" is not specified, than all the cores allocate memory according to "memory=".   

A suggested procedure is to over-allocate memory for a short trial run, that is, take a conservative stab at how much memory to allocate.   You'll then know from the d3hsp file what the minimum requirements for memory and memory2 and can use that knowlege in the full run.  Look for the words "Memory required to begin solution" in d3hsp.

The memory you allocate for a core should not exceed roughly 80% of the physical memory.    As an example, let's say you have 8 Gb memory per core.   If you run double precision, there's 8 bytes per word so the max memory you should attempt to allocate for a double precision run is 

80% of  (8e9 bytes)/(8 bytes per word) = 8e8 words

Thus, as an upper bound, you'd set memory=800m in the trial run.  Again, this is just to get the actual memory requirements for the full run.


You will find more information on MPP LS-DYNA here:

Also, have a look at appendix O in the LS-DYNA user manual I:

Let me know how it goes.