So back in the day I had a junk computer that was barely able to run some games, integrated graphics, max ran great, etc.  Got a newer computer that had a decent card, ran games, max RAN great except for the viewport.  Recent versions of Max since Nitrous was added definitely run smoother, but there is a certain issue that I've noticed.  
Before getting into the actual problem, I will say I'm on a system that's at least fairly new: (basic info should be enough right?)
-  i7-6820, 16GB RAM, GeForce GTX980
 So I can run games like Elite Dangerous on maxed out settings (or at least extremely close - minus the texture super sampling) and still get 45-65 ish fps.  MAX, in DX9 mode gives me a wonderful 70fps with plenty of mesh detail, thousands and thousands of polys and no problems what so ever.  Running in DX11 mode is a different story.  No matter what viewport view style I've chosen, they all only get at best 20fps when panning/rotating the view.  However!  if I maximize the viewport window I'm currently working in, my fps rockets up to well over 100fps.  The same behavior occurs with or without anything in the scene.  A completely brand new startup empty scene will give me 20fps whether it be shaded, realistic, or even wireframe.  When I maximize, say, the perspective view, it draws any mode with even cranked up max detail like 8x lighting and shadows, it runs silky smooth.  The 20fps is only when all 4 viewports are visible at the same time.
Again, it's not out of the question to just use DX9 instead since it gives me that awesome performance, so I do.  I am just wondering if anyone has noticed this when they are trying to tweak 3ds Max performance or if they've managed to find a solution to this, aside from maximizing the view when you want to be able to manually turn-table your work to get all those juicy viewing angles to see if you missed anything etc. etc.?  Again, this just seems to happen in DX11 mode, not DX9