But have no problems with all my other airports.. Whats wrong with KDFW
There's nothing wrong with KDFW but, instead, you clearly have a configuration problem. I have a system MUCH slower than yours ( 2.66 Xeon with 512MB ATI 4870 ), and I get a constant 32-35 fps at KDFW and every users here also found KDFW to be very fps friendly despite its size, so, it's clearly a problem of your system.
Fact that other airports are running well, doesn't mean much: KDFW is the only FSX scenery available which uses your video card to the max, since it uses shaders for ground as well.
This means, if you have a wrong graphic setting in FSX or in your Video card control panel, or a problem with the video driver, you might not noticed it with other sceneries, since they don't use such features.
Try the following:
- Go to %APPDATA%\Microsoft\FSX, take the FSX.CFG and move it to another place (like the Desktop) let FSX rebuild a new one and see if it makes any difference. If it does, perhaps there was a tweak that doesn't work well with your system.
- As explained on the KDFW manual, be sure you have Transparency Antialiasing set to off. We found this used to be a problem on ATI cards only but, you never know if it surfaced on nVidia drivers as well.
- Try to reset your video card Control Panel with default settings.
- What is the fps with a DEFAULT airplane ?