RE: Realflight G3.5 compatible?
Probably not very well.
Turn off most of the smoke and clouds and stuff and or use a photo field and you may get acceptable performance.
Video memory is a big factor, since there's no such thing as 504 mb of ram I have to assume you have 512 with 8 meg of shared ram thats used for video. System ram is comparitively slow and 8 meg isn't much.