No. If I’m running an eigenfrequency calculation I manually select the spooles solver; it is better than PaStiX in that case.
No, I have not seen that either.
The main problem I ran into is that PaStiX needs a single-threaded build of OpenBLAS (you need to define USE_THREAD=0 when building OpenBLAS). However, since PaStiX does use multiple cores, you do need to build OpenBLAS with locking enabled (USE_LOCKING=1). If you don’t do this correctly, calculations will produce weird results.
No, unfortunately not. As I understand it, some changes to PaStiX are needed to make it work with CalculiX out-of-the-box.
Looking at the publicly available issues, it is clear that Kabbone has been working on that with the authors of PaStiX, buy I’m not sure it is finished.
AFAICT, the modified version of PaStiX called PaStiX4CalculiX is the only one that works with the published sources of CalculiX.
Update: See : brand new patch for CalculiX with PaStiX 6.4.0, thanks to rafal.brzegowy for providing the link.
The latest windows binaries of CalculiX 2.23 seems to be built with a newer version of PaStiX IIRC. But I could not find out how that was done.
For the record; Python 2.7 is only used in scripts to derive code for other precisions from a template file. Python 2 is not linked in and not required for using the library itself, just for building it. Those Python scripts are not compatible with Python 3.