The Frostpunk 2 closed beta doesn't have the best performance, even on decent hardware. Fortunately, you can change Frostpunk 2's graphics settings to increase your FPS and make the game more playable.
BEST Optimization Guide | Delta Force: Hawk Ops | Max FPS | Best Settings
In the closed preview of Frostpunk 2, there aren’t many settings you can tweak, aside from the traditional Textures, Lighting, Shadows, and a few more. Below, you’ll find a list of the best settings for Frostpunk 2, based on a variety of tests I ran with the Nvidia Performance Overlay.
I'm setting the general graphics to Medium because it feels like a good starting point for performance testing. Dropping them down to Low or Very Low will obviously increase your framerate at the cost of lower visual quality. This is something you'll want to adjust depending on your hardware and desired FPS.
As I said, if you’re still experiencing performance issues, try lowering all settings from Medium to Low or Very Low. This will significantly impact the visual quality of the game, but it will give a performance boost. Switching from Medium to Low gave me an average of 10 extra FPS, which is good enough if you want to hit those 60 FPS.