Did some testing fighting mobs in the Black Shroud. I was fighting a single mob, and two other mobs were in the background. I was the only player on screen. Fighting the single mob with my basic 1-2-3 attack, while facing away from the camera and with my character between the camera and the mob, produced awful stuttering. Without moving the camera at all, I ran behind the mob so that the mob was between the camera and my character, and turned around so that my character was facing the camera. Now my 1-2-3 attack produced no stuttering at all. I switched positions several times, always with the same result.
The only things that changed in this situation were 1) which direction my character was facing, and 2) whether my character was between the camera and the mob or not. Everything that was on screen while the stuttering was horrible was also on screen while the stuttering was nonexistent. No computer settings or hardware changed between the two situations. The problem was entirely caused by the position of my character relative to the mob and/or which direction he was facing. If the stuttering was caused by having insufficient processing power, I doubt simply moving my character two feet forward and turning him around would somehow reduce the processing power required.
There is also the consideration that people with much more powerful processors than I have are hearing worse stuttering than I am - for me the problem doesn't happen with every fight, and I can always fix it by running behind the mob and facing the camera, though of course this usually isn't a practical solution. Meanwhile, people with more powerful processors are apparently unable to alleviate the problem at all, or the camera fix only works momentarily.
I'm not going to deny that the game needs sufficient processing power to run properly, to claim otherwise would be ridiculous. But I'm getting sound bugs after a major change to the sound system, in an area from 2012 that runs at 100 fps, bugs that are worse for people with better cpus, bugs that can be alleviated by slightly changing the position of my character while changing nothing else - if that's 100% caused by not having enough processing power, I'll eat my hat.