I have taken the middle display settings eg VOR lines traffic from the menu and other items off the outer display screens but found the middle to make the biggest difference. I have ORBX Australia sp3 and ybbn, just did a flight to mackay now i'm back to my 85% traffic settings and full weather radius. I am hitting around the 20's @ ybbn and 50 or so in less populated places. Hope this helps as i have i-fly as well and can run max settings but this plane is now getting there and i'm enjoying it much more great product.

What you mean by outer displays? the first officers displays? And where is this setting in the CDU?

The setting is in the FMC i just did the return flight to make sure i was sure. So i kept the navigation settings to a minimum on the map display (2 d panel captain side). So this improved the FPS much smoother 23 on the ground and around 70-80 in the air. Changing the from the arc to ctr is the same as with the vert display.

Mate, a couple of pics would help us understand your point..

Sorry if i was not clear enough for you. When you look at your panel you have your map display, go into the FMC go into menu pmdg setup, aircraft, display's pfd ang go from there and adjust what you need to. this made my performance much better. It's reduced the map display this is my setting. Rising runway, pfd/nd nps, round rad alt dial, ada dial, landing alt bar, 2500 height alert, VOR course lines ect turned OFF just the basic navigation i have and this has worked for me after sometime reducing autogen, mesh, weather and the rest trying to get better frames hope this helps you all.