I've got a brand spankin new 6900XT that is having a stuttering issue in Warzone and even Fallout 76.
What I have determined after many hours of testing, deleting drivers, stress testing, overclocking, underclocking, etc....
My VRAM is hitting 16Gb used in Warzone.
I know, crazy. It's double what's recommended for "competitive" play...
No, my settings aren't maxed out. I'm running at 1080, no RX, mostly "High" rather than "Ultra" settings. The graph in the settings menu has me using less than 6gb of VRAM, yet somehow I am hitting 16Gb.
No background apps running, etc.. vram usage is around 300-400mb when launching the game. I'm currently 45min deep into an OCCT mem test with no errors.
There are several warzone threads here. Seems like the most common thing is reducing the VideoMemoryScale setting. try 0.8 and maybe even lower. See if that stops the problem.
Take a look at: