I already know(and have felt) the frame rate drop from the taxi camera in the 300-ER. I noticed that the cameras different windows. I decided to test out a theory(unfortunately it was in the middle of a flight).

I closed 2 of the 3 windows(the bottom 2) and the frame rate shot up after deleting 1 of them). This may or may not be limited to me as you know all systems are different. When I'm on the ground(or if someone who is on the ground and willing to test it out) I'll test this out again.

So I have tested this on the ground and found that it works on the ground as well. Hopefully this helps.

Maybe I'm not understanding the significance of your findings, but all you're doing is closing the camera windows? Of course that will increase your framerates.  

Maybe I'm not understanding the significance of your findings, but all you're doing is closing the camera windows? Of course that will increase your framerates.  

It's not meant to be significant. Just something of note.