On my Mac, I'm trying to import 180,000+ images, however, I can only import about 10-20K or so at a time because Lightroom CC memory grows to consume all available memory. When that happens, I have to shutdown Lightroom and restart the import. I've been keeping Activity Monitor up while importing and I would expect memory usage to reach a stable plateau at some point. It never does. It just grows and grows until nothing is left and it stops responding.