I first pirated the game, and it ran perfectly. After purchasing it on steam, I am having weird fps problems that basically make the game unplayable. During the daytime, my fps is usually around 10, sometimes 30. Occasionally it'll go up to 60 for around 10 seconds before going down again. During scavenging it's a little better, a solid 60 around 25% of the time and then down to 30 or 10 the rest of it. I honestly can't play the game because of this problem; it's a little irritating that the pirated version of the game works better than the purchased one.
Adjusting any of the settings does nothing. Neither does restarting my computer, getting new drivers, and stopping all other processes. I've reinstalled the game three times.