I usually install games to my second SSD, which is also a sata3 ssd (mx500). The stuttering with RE 2 seems to be pretty common so maybe it's an engine thing.Huh... that's odd. RE2 had the "microstutters" for me, too - probably had a dozen of them in my entire 10 hour playthrough. Sometimes it would just "pause" for a fifth of a second; other times it would do as you say and drop to 40 fps or so... but truly, for no longer than like 1 second. Super distracting, yes... but didn't ruin the gameplay experience at all. And clearly the result of something other than the "graphics," as the exact same scene rendering the exact same thing would bump right back up.
What kind of storage do you have? I have a slow-by-modern-standards SATA3 SSD and I sometimes wonder if it's that.