Do parked ai aircraft affect the system as much as airborne ai aircraft?

I'm using My Traffic and I like to see a reasonable number of airliners at the gates when I fly into a major airport.  I don't care much how many are flying.  I just like the effect of a busy airport based on the number of parked aircraft at the gates.

Using KSFO as a standard I adjust the traffic % until I have an acceptable framerate.   Then I look at the gates and check the number of aircraft parked at them.  At 50% traffic the gates are loaded but my framerate is down to 9-12 FPS.  When I drop the traffic to 10% my frame rate is up the mid to high 20s but I still have a goodly number of aircraft at the gates.

That leads me to believe that parked ai aircraft have less overhead than flying ai aircraft.  Is that correct?

Noel 

 Parked traffic should have no more impact than flying aircraft unless you are closeby causing the LOD of the model to be higher detail regardless of what model you are using. Each users system and config plays a bigger role on this impact as there are so many variants in options from dynamic lighting, all of the various shadows, and anti-aliasing etc.

The level of detail for the AI aircraft will play a role.  Highly detailed aircraft close to you will utilize those high details and will increase the load on your computer, while the same aircraft at a good distance away will us a lower level of detail and be more frame rate friendly.  Other things that will affect frame rates when it comes to AI are shadows and contrails, both increase the processing load on the CPU.