Actually,with XP I was getting over 45 FPS at airports and with add-on scenery like the popular Vegas addon on that improves the Strip's look. I would hardly be complaining here if the difference between my XP installation of FS9 and the installation on 7 had only minimal differences. The difference is very dramatic and aggravating as I don't enjoy flying with rates fluctuating between 7 and 14 much of the time at ground level. I would have expected that no one one need to lecture me about the difference between FPS at altitude, vs near/at the ground. I thought I'd made that all abundantly clear.
AND WHY IN THE HECK ARE YOU TALKING ABOUT FSX? I have FS2004 (FS9).
You didn't read my posts carefully and therefore assumed I was comparing apples to oranges.
Regardless of the version of the simulator the FPS at altitude are always going to be higher than at ground level because the scenary complexity of each are polar opposites.
Your thoughts as they are posted tend to at least leave the impression that you think the rates of scenary should be homogenous across all altitudes and that just isn't the case no matter how you want to kick and scream about it.
As for add-ons, they don't replace the entire graphics set of the flight simulator. Portions of the graphics sets that come with the flight sim are still employed during a flight despite the installed add-ons. And to be certain you can bet the add-ons are enabled for use during low altitude flight particularly so when the add-on was created to enhance the low altitude scenary by various means including invoking certain features of the graphics engines employed that the FS OEM has included OR by employing dynamic graphic engine substitutions supplied by the add-on manufacturer.
It is entire probable that once the FL or cruise altitudes are reached the FS graphic scenary will take over because there is nothing to be gained by a "low altitude" scenary (airports, cities and etc) add-on manufacturer designing high altitude scenary when everything at the high altitudes dithers across the board and detail becomes more of a wholistic blend. And if the add-on manufacturer is substituting engine graphics libraries it is entirely possible that once altitude is reached the same graphics computations are shared between the OEM and the add-on.
Lastly no one here including myself is trying to lecture you. I am trying to get you to understand that you give a firm impressiion that you have an over-simplified understanding of how graphics scenaries function when it comes to FPS rates. If you don't like what you are hearing that is not the fault of the person trying to explain something about a subject you clearly fall short in understanding the complexities of.
And my saying that is not to slight you....no one on this planet understands everything about anything. So quit letting the rationalizations of the ego get the best of your better self and let folks try to help you over the hump on this.