[P3Dv3] Performance drop

Hi all,

I'm experiencing a performance drop using the 737 immersion effects.

Performance may drop about 60% from a stable 60 fps without active effects to only 15-20 FPS with effects.

This drop happens with volumetric lighting and wing condensation. All other effects work just fine and without any impact.

Will there be something wrong with my settings? I've tried reducing Special Effects from 'High' to 'Medium' but no noticeable changes there.

I run Prepar3d V3.2 on Windows 10, i7 6700K @ 4,4GHz, 16gb RAM and a GTX 970.

Any help will be highly appreciated!

P.s. this also happens with the other immersion packages I've installed.