I've noticed this for awhile--at least 1.5 years--but still surprising after just upgrading to a Mac Studio Ultra from a MacPro Intel machine. I've got 64GB of RAM, have a huge NVME scratch, and am using the internal NVME drive for OS, apps, and data--plenty of storage space with R/W speeds near 5700Mb/s.
I'm wondering why my import/processing/export tasks are so much slower with my Nikon Z7 raw files than my Fuji GFX 100S raw files. I'm usually importing folders of 100 or so images and applying Develop presets which include exposure, custom profiles, and some gradient masks. When I edit in LR Classic Develop module and paste a full set of settings from one file to a set of say 10 images (no AI healing, which I know adds more compute power), the Nikon files take like 3X as long as the Fuji files to apply. Importing is much faster with Fuji as well, even when doing full size previews of 100MP files. While I haven't timed it, I believe batch exports are slower as well, perhaps at least 20% slower.
Could the use of the built-in lens profiles in the Nikon lenses add processing time? (The Fuji files have individual lens profiles.) When I look at the CPU processes during export, LR rarely uses more than 30% of the computing power and not much more than 30GB of RAM, so it doesn't feel like LR is using all the CPU and GPU that it could. The other thing I notice is that with the Nikon files in either Grid or Develop mode, when I zoom in, it takes 2-5 seconds to see the 100% view size, while the Fuji files zoom in instantaneously. Both have 1:1 preview rendered.
Suggestions to improve my Nikon workflow are welcome.