trying something different. Mac OS is on my boot ssd, my photo collection on another ssd, and my apple photos library file is on its own ssd. trying to see if it makes a difference as far as speeding up the process, as you know, if they are all on one drive, then all the overlapping read and writes slows things down, but if the drive load is spread out, should speed up things. I know that importing into photos library puts a lot of work as evidenced by the non stop activity on the photos library ssd, while all the photos are on its own drive. seems to be mainly down to cpu speeds, this way, now. from previous iterations, my ~670GB photos collection, results in the apple photos library file ballooning up to over 1GB, just because of thumbnails and all that data to keep track of the photos, and all the facial recognition metadata that also fills out that library.