I have the top tier Wacom Mobile Studio Pro (i7 16gb RAM) but I'm still getting lag issues. The task manager says Photoshop is only using around 1500mb of RAM (45% of my total) and I've set Photoshop to allow to use 90% of the memory. The lag happens when I'm moving back a step or undoing, it takes like 5-10 seconds before it does anything and I use the lasso tool very heavily. The first stroke is fine but when I use shift and alt to add or omit sections of the selected area, it takes a while before it does anything if anything at all. The file I'm working on has 600 layers or so. Before I got the Wacom I Tablet, I worked on my desktop which has an i5 and 8gb of RAM and it worked perfectly fine. What is going on? Help me.
I also have this same exact issue on a Huion cintiq I've been trying to fix for a few days. Very frustration. The file I'm working on has about 30 layers. I switched my GPU performance to Normal and it seemed to help but the zooming lag persists. Not sure why a GTX 1080 is causing lag as it shouldn't. Turning GPU acceleration off still causes Zoom lag.