I've noticed this in previous versions but never tested it out until now. I've noticed that on my default settings I get an occasional hiccup every 15-30 seconds on average while in straight & level flight (that is, the sim will freeze up for about 1/4 second, then resume). After playing around with some of the settings, it seems most of these hiccups are related to higher MSAA levels.
MSAA off: no hiccups
MSAA x2: no hiccups
MSAA x4: every 15-30 seconds
At all of the above AA levels, the framerate counter never deviates from 90 or 91 fps.
Does this sound like a bug related to the software? Or do you think it's a hardware bottleneck that you can't do anything about?