Should compare 1080P/720P/320P and zoom. Seems performance is different based on those and the raw image will differ between 1080/zoom/720. Taking a crop of that may give you a higher res but I'm looking at the 720P mode stuff and its not as good as 1080 or zoom.
But better res vs more frames... I dunno. You don't have to turn global draw off completely, just shut down things like zebrase, etc.