Hello,
I'm trying to multibox 5 instances on WOW but I am having FPS problems. (It frequently drops to 15-20 FPS. There is also often a few seconds of delay between my main and the other accounts).
I noticed that my CPU is running at 100% of its capacity when I play. I am suspecting it's the problem. I just want to make sure it is the case before purchasing anything. I am a beginner and I am not sure what's the requirements for running 5 accounts at once.

Here my setup :

Win10
Z390 Gaming X x64
intel Core i5-9600k @ 3.70 GHz
32GB RAM
GeForce RTX 2070
Isboxer
Screen resolution 4k
Target FPS : 60 FPS main, 30 FPS other 4 accounts
Graphics currently turned to the minimum.