OK - I've posted this as a question about FSX, not a statement of fact since I really don't know.Could the reason for significant decrease in FPS be due to high texture quality of AI planes and/or a functional cockpit being made available for AI planes (both GA and Airline traffic)?I ask this because I thought that with FS004 (my memory is terrible, so I may be all wrong here), the textures of the AI aircraft were much higher than needed (for the visual affects and reason for AI traffic being used). That's why PAI and others produced lower texture planes - to have a much less impact on FPS.Also, when I added some AI traffic to my local airpot in FS2004 using Lee Swordy's AI Traffic program, I thought he made it clear that we should use lower texture versions of planes and those that do not have functional cockpits. This would give us high AI traffic with little impact to FPS.Can someone check the corresponding FSX file that's comparable to the FS004 traffic.blg file? I know, the FS2004 file is called something different, don't recall off hand, but you get the idea.Maybe the AI traffic used in the FSX default install is just too much for what we need?JerryG

I am using the old Flight One Ultimate traffic set up I had in FS9, I copied over the ai aircraft and traffic files I used in FS9, disabled the default trafficaircraft.bgl.Using what I consider to be MEDIUM settings, with AUTOGEN OFF and traffic set to 100%, I am achieving a frame rate of about 10 at EGCC, with the same sort of settings I got a frame rate of about 20 at EGCC in FS9.Why the big jump I thought, well I thought it was the shear amount of AI traffic that there is just running in the background of FSX, with the road vehicles, ships and ferries, and leisure boat settings at 50, using the TrafficTool box SDK I had over 360 AI objects moving around in the active areaof which 109 were AI traffic, put the sliders to 0% my frame rates jump up by 2 fps, to me not a big improvement.I personally think the biggest frame killer is the AUTOGEN textures, on my rig it will just knock the frame rate to 3 or 4 at EGCC with AUTOGEN on so I have turned it off, until either a new set of textures and objects appear or I can afford a new more powerful rig.I do agree with you that using the default aircraft as AI is overkill, but the amount of traffic the default AI traffic gives will not have too much effect on your system