Scratch disk is a separate drive. Mine happens to be a hybrid SSD/HD, but the point is that it is a separate drive that is only accessed occasionally and does not get hit by the OS and native apps running.
Running Adobe CC and staying up to date, I make sure my gpu drivers are relatively updated. I depend on GPU acceleration wherever I can get.
Lots of system memory too. I leave Illustrator, PS, and ID, open all day. A chunk of my system memory goes to the page file cause windows is going to manage resources how it wants outside of what Adobe products do, so for long term performance, a healthy page file is good.