I am getting ready to build a system to run both sims here as follows:Intel Core Duo E6850 ( i would have chosen the Q6600 , but i am not running Vista at this time and do not plan to o/c)NVIDIA 8800GT2GB OCZ DDR1600 RAMNow, i am running an AMD 4800 Dual Core with a 7900GT at the moment, and running the sim quite well( FS9). However , when landing at a complex airport ( e.g. FZ02 Portland,) with heavy weather and a complex a/c , my computer struggles to keep up. Frame rates go down in the mid-teens , and fluctuate greatly. Is anyone running FS9 with the specs close to the above and how is your peformance in complex weather/ac and airports? In addition, ever since i upgraded my monitor from a CRT (1280*1024) to a LCD ( 1680*1050), my cloud performance has gone down big time. I like to run 8xAA on my video card , but with a big time performance decrease when running heavy cloud. Basically , i would run FS9 for heavy iron and FSX for GA.... I know with this setup i can pump the settings for FSX quite high ( not maxed out of course) with decent FPS.Thank youRobAMD 4800 Dual Core1.5 GB RAMNvidia 7900GT

Good choice with your CPU. Re 8800GT, since you are not going to Vista you may as well just stay with your 7900GT, as your low FPS are likely not being caused by your video card, even at 8xAA.The following chart shows just how little your video card matters in FS9. This benchmark is run with all sliders right in FS9 on a C2D 3.2GHz CPU and 7900GTO GPU. Normal = 1680x1050 and Spanned = 3360x1050. As you can see, it takes 8XS/16AF @ 3360x1050 before the video card starts to come into play, and even then it has the same lowest FPS as all the other GPU / display settings - ie. the CPU, not the GPU, is determining the lowest point.http://forums.avsim.net/user_files/180776.jpgI don't know what DDR1600 RAM is, but as long as it isn't any more expensive than DDR2-800, which will do you just fine, then all will be good.Gary