NieR: Automata is a bit of alright, though it appears the game's performance on PC isn't the best on some configurations. If you've been struggling with frame rates, a new user-made tool promises to make all your lag-free dreams come true, if you're willing to jump through a hoop or two.
The tool, called "Fix Automata Resolution", or "FAR" for short, is a part of a larger tweaking suite, "SpecialK". Created by one Andon M. Coleman, who goes by the handle "Kaldaien", the utility provides access to various performance settings, including frame rate limiters, vertical sync buffering and resolution scaling.
Unfortunately, while the Steam community thread has details about the settings (and a download link), it doesn't have much in the way of specific usage instructions.
For that, you're better off checking out this Reddit post:
Then once in-game, press Ctrl+Shift+Backspace to bring up the settings and reduce Global Illuminatoin [sic] workgroup to 16 from 64. I only noticed a change in Lighting when i set the GL to 0. Between 16 and 64, there was no noticeable change but the FPS improved immensely.
The post mentions using the "testing" branch, but according to RPS' Alice O'Connor, the feature is now part of the tool's main branch.
You might have to play around with the global illumination value to find what's best for you. Hopefully, Square Enix incorporates the tweak (or at least, provides access to the setting) into the game itself, so the playerbase at large has access to it.