FSX reinstalled on Dell Latitide E6400 with Nvidia Quadro 160M graphics, after upgrade to Win7 64 bit, 4GB memory.
Same computer with XP had satisifactory performance, frame rates 15-20 at native screen resolution.
After win7 upgrade, fsx (expansion pack=SP2) starts out at 20fps or higher, but after a few minutes slows to 1-5 fps, irrespective of scenario, and almost independently of the graphics settings. Even setting to low resolution and low textures doesn't prevent the degradation.
So I suspect the Nvidia driver (latest, tried previous), and some setting incompatability. Any suggestions? Trying each setting and combination (and restarting FSX, waiting for the slowdown) etc is impractical.
Running in XPsp3 compatibility mode made no difference. Clean startup made no difference.