Major change in performance

I recently started getting much poorer performance with a lot of micro stuttering and rubber banding.  It is intermittent and will alternate between relatively smooth (what looks like 20+ fps), and choppy.  The Zwift log says my fps is at 12-14, which is much lower than I’ve previously gotten on my rig (i7, 560ti).  Even on the log in screen the background image runs much slower.  According to nvidia inspector my card is running at 99%, which seems overkill when I can run Crysis and Battlefield 3 with no problem in 1080… anyone else experience an issue like this?  An idea what might cause it?

would like to hear more on this. i am running an alienware alpha with 8gb ram and ssd. it was super smooth and then the last week or so it is not jumpy/choppy. seems to be after the last update.