08-17-2020, 11:43 AM
(08-17-2020, 02:28 AM)ceanwang Wrote: The program set the largest number at 14000000, you ask more than that, sure you will get a warring.
You need to raise that largest number in the program.
I'm somewhat skeptical of the meaning of "just change the max value" -- they must've set it at 14 M for some reason. Keep in mind the doc where they claim to have gotten it to alloc 2 GB also mentions it having been "a lot of work".
But even if you DID change the max value and that didn't break NASTRAN-95's memory management strategy outright (which I find unlikely), you'd still be limited to 2-4 GB max, which is still not enough for commercial-scale models. Keep in mind those models require more than twice that to even pass the checks, and are often alloc'd several dozens of gigabytes' worth of in-memory database in order to run in reasonable amounts of time.
All in all, rewriting the memory management code seems like so much of a hassle... It pretty much sums up how I feel about NASTRAN-95 as a whole: it's an outdated program; it can't run models output from modern CAD software, and even after converting unsupported elements (lossily so), it still has hard limitations on scale, run time, and output quality. It's good, in the name of science, legacy and all that, that we got it to compile and run on modern machines, but we shouldn't put any effort into trying to improve it. Well, I certainly won't.
We should keep good docs on this amazing piece of legacy software, let it inspire us when possible, but focus actual work on more modern OSS solutions like MYSTRAN.