Fix: turn down "model render distance" and "detail render distance" under tools/options/3D views. (For my computer, I've found turning either of these up past 500 units, makes the 3D view choppy and utterly unlook-at-able :)) One may be more of a gfx card drag than the other, but i haven't tested that far... experiment to see what the optimum settings for your rig are!