In that example it is only 900 or so photos, but I have now add more and am now at the 2500 limit. I’m using the steam paid version. This behavior seems to be normal, as it has been working like this for years. It was my understanding that alignment would use as much RAM as needed to for the amount of features you have selected in you settings, and that other processing after would be out of core (like depth mapping). At the time I was told this by Wishgranter. I assumed he worked for Capturing Reality, as he was very knowledgeable and responded to almost every post, but have been told by the forum that he was just a guy helping out.