There are quite a few recent posts on this forum where users complain about sudden performance issues since October or November 2017. There also seems to be a problem with how ASW (Asynchronous Space Warp) performs since around that time. Here are two examples of these posts:
Many people speculating whether Nvidia drivers, a Windows update or whatever is the culprit.Yet, although this is a SUPPORT FORUM, there's no official word from Oculus staff on these issues. People are left in the dark about the possible reasons or a way on how to fix this. To us, the situation is very serious, as we develop VR apps and are confronted with these questions by our clients, but can't give them answers.