I am using Nastran 2018.2. I see that Patran put this system(216) command into my bdf file. However, when I look in the QRG for 2018, there is no entry for system cell 216. So what does this undocumented feature do?
Oh. Ok. I have been using the command SMETHOD=ELEMENT to turn on the iterative solver. So it sounds like this is a bug in Patran and that the System(216) is not only undocumented but also obsolete. Maybe it should get put onto a list to get fixed.
SMETHOD=ELEMENT is specifically turning on the CASI iterative solver... the ITER bulk data entry will allow other options. I assume Patran is adding that system cell due to a selection made in the SOLVER options?
This can give a good idea of the various speed-ups for different solvers, memory, parallel, etc. Of course, everything is model dependent so you will have to see what works best for your specific situation.
