The problem occurs when I am looking at my displays and out of the window. It happens with all my PMDG products expect the 737 occasionally. Also this only happens during cruise. When I am at a default airport that is small. I get 30 FPS  in the VC with all PMDG aircraft. But as soon as I start cruising my FPS goes to 15 and seems to be locked there until I land. My FSX is set to unlimited and locked via Nvidia Inspector. I use REX and it is not the clouds because even on clear skies it happens. I achieve 30FPS any where else during cruise except when looking at my displays and out of the window at the same time. 

 

Windows 8.1

Alienware X51 3.4GHZ

Geforce 660

 

It is not a cpu related problem I know

 

Dane QUartel

What is your water setting? It's not about PMDG, it's about the cloud, water, autogen etc that dragged your fps. When you look at your overhead panel, your graphics card does not draw clouds and water so it gains back fps.

Try changing the DU refresh rate to unlimited in the FMC.

 

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