Presence of Oculus Runtime Drivers on they system may cause micro-stutter, manifesting once every few seconds, as the game's video freezes for a fraction of a second, then resumes. Audio is typically not affected. The timing of the stutter is very regular and seems to be related to network activity (Oculus drivers pinging home at regular intervals when present).
To avoid this issue, disconnect from the Internet altogether. Blocking the game's executable using firewall does not solve it.
Alternatively, uninstalling or manually stopping Oculus drivers also resolves the issue.