So far I've found XP 10.42 runs pretty well, and on the whole runs smoother than P3D, but there are some things that are kind of puzzling. I have the Carenado King Air B200 for XP (really nice, I love it!) and it really hurts the frames. Even with fairly modest settings (shadows off, no car traffic, no water reflections, 2x SSAA/FXAA, objects/roads at "Tons") there are a lot of areas where I can't even maintain 30fps. Extended DSF scenery is not turned on either, although I tried with it on and it didn't affect my frames all that much (at least not compared to how the B200 does.)

 

My PC is fairly stout - i5 3570k @ 4.6ghz, 16gb DDR3 2400mhz CL10, 980 Ti, Samsung 850 Pro SSDs.

 

I'm hoping someone has some tips on key settings that can help FPS a lot in X-Plane

So far I've found XP 10.42 runs pretty well, and on the whole runs smoother than P3D, but there are some things that are kind of puzzling. I have the Carenado King Air B200 for XP (really nice, I love it!) and it really hurts the frames. Even with fairly modest settings (shadows off, no car traffic, no water reflections, 2x SSAA/FXAA, objects/roads at "Tons") there are a lot of areas where I can't even maintain 30fps. Extended DSF scenery is not turned on either, although I tried with it on and it didn't affect my frames all that much (at least not compared to how the B200 does.)

 

My PC is fairly stout - i5 3570k @ 4.6ghz, 16gb DDR3 2400mhz CL10, 980 Ti, Samsung 850 Pro SSDs.

 

I'm hoping someone has some tips on key settings that can help FPS a lot in X-Plane

Objects and particularly Roads will put a heavy strain on your machine. Try turning these down to minimum, restart XP and work from there, adding them until you get reasonable performance.

 

I have found that with XP, having more RAM also does help, I upgraded to 24G of system RAM but still not running roads at all, I have objects set to "Lots".

An often overlooked performance hit is the "cloud puffs" they can kill your FPS , especially on a multimonitor system.

It could be your texture settings as well, these can kill even quite a powerful computer (Although you have a good graphics card). If you have textures set to maximum, make sure you tick "Compress to save VRAM" which makes quite a big difference. If you can live with slightly blurrier textures, lower it down a notch. 

For me the answer is that Carenado ACs are simply not optimized for XP. I like them but I suffer the same huge impact on FPS compared to other payware aircraft. Since I don't like FPS lower than 28-30 I just use autolod or Terra Haze to increase LOD when I fly my Carenado. I really hope IXEG will not impact on frame as Carenado does.

I have a very beefy system (weak spot is the graphics card at only 4GB) and I have no problem running any of the Carenado aircraft.  I backed my HDR AA and my AF settings down, use "compressed textures" and pretty much put everything else where I want it - extreme airports and textures, tons of roads and objects.  The only time I see frames drop below 25-30 is if I fly into a dense scenery area where there are errors in Custom Scenery files that the computer is trying to resolve in the background while keeping up with the flight model.  Most of the time over "normal" country, I'm in the 60's or better on a 32" 2560x1440 monitor.

Try reloading the aircraft, I find the same problem as you but simply reloading the aircraft perhaps with a different colour scheme brings acceptable framerates.