PSB files live on a 7200 RPM external drive connected USB 3.0.
I'm often working on layered PSB files that range from 3.0 GB to sometimes 15.0 GB in size with lots of smart objects.
PS Scratch Disk is set to external SSD connected USB 3.0.
Brush, Select & Mask, and moving around the image when zoomed in 1:1 are all absolute torcher. It's extremely laggy...regardless of the size of files. It seems slightly better briefly after a reboot and clearing memory...but it doesn't last long. Trying to determine what the bottleneck is...or if I have some performance settings that need adjusted. I'm overdue for a new computer I realize but I'm concerned if I don't know for certain what my bottleneck is, a new computer may be plagued with the same issues.
I've reviewed this article on PS Performance preferences in an effort to optimize my system...have experimented from there a bit. Still seem to be missing something.