I also got some harsh drops to 10-20 fps during and after cutscenes. I'll update OP with any more possible performance fixes I come across. I installed this and I think I saw performance improvements, but it most likely was placebo.

Someone on Steam forums said that EA/Motive's official Nvidia driver version for the game is 527.37.

I'm FAIRLY confident I saw a performance increase when I did this.

Sitting in a Discord voice chat lowers my frames by a lot so I stopped doing that.

I still get microstutters, but I think pretty much everyone deals with them. I did this and replayed the first chapter and framerate drops completely went away and my game runs at a buttery smooth 80 FPS on Medium graphics.

Disable Motion Blur in in-game settings.

Install Vulkan Translation for DirectX into your Dead Space game files.

I tried everything to fix the problem and I finally found a fix that worked for me and I wanted to share to help anyone dealing with this issue too.

This was especially annoying because it makes the game way scarier when I have to fight monsters in 15-20 FPS when my game was running at like 70 FPS right before that combat encounter. Previously, I was having issues with my framerate dropping at random points in the game.

Dead space pc framerate