Hello!
This is not exactly correct, NX NASTRAN provide two executables in Windows x64 platform: regular
NX NASTRAN LP-64 executable that can allocate up to 8 Gb of RAM memory (this is the solver I run by default when the job do not require more than 8 GB RAM, allowing most of the RAM for I/O OS cache), and
NX NASTRAN ILP-64 executable that can allocate approximately 20 million terabytes. Practically speaking, there are no machines currently supporting more than half a terabyte, thus the amount of memory these executables can allocate is only limited by the amount of memory installed on the machine.
When the LP-64 executable is used, the bytes_per_word is 4. When the ILP-64 executable is used, the bytes_per_word is 8. This difference is important when you are specifying memory in "words" with the “memory” keyword.
Also, regarding Parallelism in NX Nastran, we can say the following:
NX Nastran supports both shared memory parallel (SMP) and distributed memory parallel (DMP) processing:
SMP is used only for lower level operations such as matrix decomposition and matrix multiplication for all solution sequences, including NonLinear Static analysis (SOL106). Therefore, as long as suitable hardware is available, all solutions can utilize SMP processing.
The
DMP is based on domain decomposition on geometry domain or frequency domain, or load domain. DMP methods achieve their solution speed by dividing the FE model into smaller pieces to be solved simultaneously. This division is performed with respect to geometry or frequency range individually or both at the same time. Although each processor is working on its own partition of the geometry or frequency
range, it communicates with the others to share information. Once the solution is complete, the results are merged, creating a single result file.
They are for linear static analysis, normal modes analysis, and frequency response analysis, respectively. Modal frequency and transient responses require computing modes for modal space. Therefore, DMODES can be applied during mode computation. In design optimization, if it involves computing modes, DMODES also can be activated.
In summary, DMP computational methods support the following solution methods in NX NASTRAN:
• SOL 101 Linear statics.
• SOL 103 Normal modes.
• SOL 105 Buckling.
• SOL 108 Direct frequency response.
• SOL 111 Modal frequency response.
• SOL 112 Modal transient response.
Best regards,
Blas.
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Blas Molero Hidalgo
Ingeniero Industrial
Director
IBERISA
48011 BILBAO (SPAIN)
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