Prepar3D v2.4 bad performance

Hi all,

Well I got a new graphics card (EVGA GTX970 FTW 4GB RAM).

I did a test flight last night and was somewhat surprised at the results.

I flew aerosoft airbus a318 from new York to London city airport. My video memory usage went from 1.5gb to 2.9gb by the end of the flight. Performance over the ocean and high altitude over land was stead 25fps locked at 26.

The problem is that when I came in for landing into London city my fps dropped right back as low as 15 on approach with very little clouds displayed. All settings are stock settings on p3d eg scenery all set to standard or normal settings.

Just wondering how I would go about tweaking p3d to run much better on stock settings as I have fsx and have read that default settings on p3d are equivalent of high settings on fsx.

My specs are:

i7 2600k OC @ 4.3ghz

8GB DDR3 1600 RAM

EVGA GTX970 FTW 4GB

Windows 7 Pro.

Any help to improve performance would be appreciated.

Thanks

Chris