I recently upgraded PS and have Ver 24.01. I have used PS for years. I am running Windows 10, latest upgrade. Previously when I would save a layered TIFF (Ctrl, Shift, S) to my external hard drive it would take 15 seconds. These were very large files, often 400-600 MB. I would then flatten the layers and resave dropping the file size to 60-80 MB. That would take 5 seconds. Now when I save layered file (same size, same hard drive) it will take 20-30 seconds; that's acceptable. But when I flatten the image and save it can take 60-120 seconds and often it will hang up at 99% saved for minutes.
I just timed a save and it took 22 seconds for a layered file (650 MB) and 2 minutes, 10 seconds for the flat file (107 MB). Again, same system, same camera (R5), same hard drive, same USB port connecting the hard drive. No other programs that I run (Topaz DeNoise AI, DXO Pure Raw, etc) show any slow down. When I convert to JPEG for web, using Ctrl, Shift, Alt, S, the files save as fast as previously.
Any thoughts as to why the flat files save so slowly now and much slower than a much larger layered file?