Stutter solved! Turns out it is my monitor, swap it over yesterday and stutter is gone! That explains no fps drop or spikes in the timeframe as well as countless setting changes yielding no positive outcome. Thanks for all your input.
So in the end it was your original diagnosis and our original suspicion it was hardware related. Now get a proper hard drive and you will be laughing!
Was using Samsung 32inch TV, switched temporarily to my old work Philips monitor to see if it made a difference which it did, now on the hunt for new decent monitor.
Perhaps the HDMI bus was the culprit or maybe the TV has a higher MS response time? COuld also be some imaging processing going on. Good that it is solved, with a decent new monitor you should be able to get a higher refresh rate and Gsync would be a nice-to-have. This actually taught me that freesync doesn´t work on Nvidia cards if using HDMI, you learn something new every day.