This game seems to really favor CPU usage quite a bit, it runs very well most of the time. The only exception is when there's a lot of mobs, damage spam, and damage particle effects going off is where I noticed a decent amount of dropped frames. I typically disable others effects, and only see my own. I'm on a 7950x3d. The main issue is that I'm seeing the status as restrained for this process in project lasso. Which could be an issue. I typically run the game in 1920x1080, windowed on a ultra wide. Paired with a 5090. The only changes I made to this process were switching the priority to normal for CPU,I/O and GPU, alongside always choosing the vcache cpu cores. I've tried with and without the priority and chosen CPU cores setting, it still shows restrained. Also made sure that it was my active window for at least 5 minutes before referring to the status(just in case clicking off caused it). Included an image for reference.
You're running a CPU-heavy game (lots of mobs, particle effects) on a 7950X3D paired with a 5090 GPU.
It sounds like you're experiencing performance issues with your game, particularly during intense moments with many mobs and effects.
The need for high CPU resources to play the game really needs better optimization. Project Lasso will truly need appropriate adjustments to ensure optimal gameplay and visuals.