I decided to wait, and went ahead and deleted the demo from my disk. Here's what I posted on the developer blog, after they posted the "tips for better framerate" post. thanks for this post. I did exactly as described. However, I still think there is a problem with X-plane 10. I am running the latest version 10.03b. I have 8 cores all running below 50% average, and GPU never exceeds 75% usage with HDR on. I get 30 fps at KSEA sitting on ground blue skies. As soon as I reach 4000-5000 feet, FPS descent to 10!!!! 10-12 fps. GPU is the same as well as CPU. there is definitely something wrong. I can’t be out of RAM for sure.. I have WAY more than 4 gb. If I put everything to default, and HDR on, and 40% clouds, I still can’t MAX the GPU Activity, nor the CPU activity, nor the memory ? How am I supposed to find the “bottleneck” ????? It has to be Bus speed. Anyone here knows how I could check that ??? Here's the response I got back on the blog: Chris Serio says: December 9, 2011 at 6:32 pm No one’s denying that there may be something that can/should/will be improved in the sim. You did exactly what you’re supposed to and you now know that your bottleneck is not your CPU or GPU or RAM…so perhaps it’s bus bandwidth. You can try to reduce things that consume bus bandwidth. This also means you can INCREASE your settings so that you consumer more CPU/GPU and make the sim “prettier” without hurting performance so long as you don’t increase bus traffic. We’ll be getting to performance tuning soon where we can talk in more specifics and we’ll have tools to help figure out what’s going on. In any case, I have to let go. I spent too much frustrating time trying to improve for flyable sim. TO me, having to reduce the number of roads to improve FPS is ridiculous. Less roads mean a lot of houses, line up in the green environment with no roads leading to them, which to me.. is not PLAUSIBLE at all. Until 10.XY comes out, when they fix this, I will certainly not spend any money on X-plane 10. I switched back to version 9 now, flying high in the sky :-) at 50-55 fps at 3840x1024, all maxed out settings. what a deception Patrick