Memory Allocation
Memory is dynamically allocated for a run. The allocation starts with the initial memory (or minimum, memory).
The default setting for the upper bound of the dynamic memory allocation is 8 GB. This setting
can be changed by using the SYSSETTING option
OS_RAM
, or by defining the -len
option in the
run script, or OS_RAM
in the configuration file. The script
overwrites the environment variable.
OptiStruct will always attempt to assign enough memory for a minimum core solution.
The initial memory is 10% of the dynamic memory upper bound by default. This setting can be
changed by using the SYSSETTING option MINLEN
,
-minlen
run option, or MINLEN
in the
configuration file.
A check run can be very helpful in estimating the memory and disk space usage. In a check run, the memory necessary is automatically allocated.
The solver automatically chooses an in-core, out-of-core, or minimum core solution based on the
memory allocated. A solution type can be forced by defining the
-core
option in the run script; the memory necessary for the
specified solution type is then assigned.
Refer to Memory Limitations for detailed information on the following topics: virtual versus physical memory, and automatic memory allocation versus fixed memory runs.