Didn't want to start a new thread but found something today that caused 1fps drops randomly, with a visible stutter on screen in various games on my setup. I game at 75 hz (no gsync) and kept seeing drops from 75 to 74fps randomly even though CPU/GPU usage was well below 100% on both.
(I conducted a long round of testing to find the culprit/trying different things each time)
Finally, I stumbled across the fix to the issue when I went on this site
https://www.vsynctester.com/ I noticed that every once in a while it would drop down to 74.5** hz, I decided to close Afterburner and try the site again, it settled on 75Hz and stayed there for 10 mins with no hitch EUREKA! Initially thinking it was an overly ambitious GPU oc I reset the clocks but it was still doing it? Then I noticed I still had the fan profile active so disabled that and VOILA it once more remained at 75hz for as long as i wanted it to. This was repeatable every single time so I knew I had found the culprit. I've been gaming all evening without any of these annoying random micro 1fps drops. I then added the fan curve profile back and again the random 1fps drops, conclusive evidence but now thankfully FIXED
To conclude, I had a fan curve profile setup on afterburner which was causing it, if I set a fixed fan speed it no longer happens. No temp issues at all on my hardware .
I understand this will not be the case with the majority but anyone who uses afterburner with a fan curve and is also having random 1 fps drops, try a fixed fan speed. It may be your solution to this annoying problem.