Hello MikeM,
Sorry for such long delay.
Currently basing on the project I assume that the following reasons are the main cause of the long alignment operation:
- the base frequency of AMD Epyc 7401p is 2 GHz, so since the alignment utilizes CPU only, the performance will be better on faster CPU. (from the report comparison it is possible to see that GPU-supported matching stage is about 3-4 times faster on your Linux machine compared to Mac Pro),
- big number of calibration groups due to the different image dimensions (result of cropping during scanning?),
- many false matching points seems to be detected by the edges of the images - according to the View Matches dialog each image have maybe a few hundreds matching photos due to the false information. If you are using scanned images, it may be reasonable to apply masks to the auxiliary information by the image borders, however, it could be much easier, if all the images have the same size, then you could just import the same mask image. Otherwise, you could mask the auxiliary information outside the actual image area only on the few images and then use Apply Masks to Tie Points option during image matching, so that all the tie points that could be found under the masks will be filtered out. This, however, shouldn't give huge impact, as I expect.