Hi Gary.
I normally fly with the frame rate set at unlimited but I tried it locked at 30 and no change, however, I did cycle through the cockpit views ("w" key) and there was no frame rate hit in the extended 2D view or the basic 6 gauges view and surprise surprise, when I returned to the default 2D view the problem appears to have stopped there also.
I need to do some further investigating to make sure it's not something to do with the area that I'm flying over. I still can't understand why the 3D view is fine because I was always under the impression that the 3D cockpit was way more demanding on the display than the 2D?
Watch this space.
Zaphod
