C1 using Session, images taking up to 5-6 seconds to load, and really long lag time using tools and adjustments!!!!!
Since v21 this has been a concern, and with the new new up date real bad !!!!!!!!!!!!!
I work with C1 nearly everyday on the same two machines .
I have up dated and done a clean restore on the 27 inch iMac that I have been using for the last 4 years that do all my editing on.
I also have lowered the preview image size to 1920 in the preferences
iMac (Retina 5K, 27-inch, 2017), processor 3.4 GHz Quad-Core Intel Core i5
memory: 16 GB 2400 MHz DDR4
graphics card : Radeon Pro 570 4 GB
MOS Carolina 10.15.7 (19H1323)