Check the average fps between both. 3fps is run-variance. The minimum fps being higher has nothing to do with MSI mode, it's just sometimes the benchmark has a single frame hitch as the benchmark loads which is registered against the metrics, just like how RTSS logger will capture a single frame hitch at say 15fps when you exit a menu even though the rest of the game is say, 85fps. The average fps dictates the baseline of that run, and 3fps is easily within run variance as the same difference can be observed running the benchmark back to back a bunch of times too after closing and re-starting the game.
I think at the high end of the HW scale, the differences are negligible, it's probably more noticeable when a GPU can benefit due to being a midrange card etc.