Performance drops up to nearly 80% when accessing full inventories. I had a field vest, gorka jacket and pants, utility belt w/ holter and canteen, sposn tortilla bag, and combat boots with combat knife. Upon accessing my inventory, my frame rate was dropping about 20-30 fps, which wasn't too bad because I was going from 100+ to approximately 60-70fps. But, upon accessing my vehicle's inventory (which was also nearly full with weapons, car parts, and ammo), my framerate was dropping to ~20fps sometimes lower.

PC Specs:
GTX 1080
i7-4790k @4.5ghz
32 gb ram @2400mhz
Running on an SSD