I have same problem with 777 Immersion, and I found out that my contrails is different from the official video or other flyer(something like engine spray come out from T7 wing)
it cause huge impact on my FPS..
When I uninstall 777 immersion, it return to normal.
Can anyone help me to solve the problem?
Steve DX10 Fixer
Active Sky Next
REX 4 Texture Direct
FSX installed in Samsung 840Pro SSD