Are those shots with fs9? they're pretty nice. the runway textures are great!
when was the last time you ran FSX? the sim had a big problem when it was first introduced. Pre sp1 would only grant you 3-4 fps at the runway no matter what kind of rig you had. On my laptop with a 1.6ghz c2d 2 gigs of ram and a nvidia mobile 7600 gives me about 20 fps consistantly on medium settings (a little lower at the runway, or very large cities with alot of autogen enabled and of course bloom and AA turned off) The quad, even at stock speeds far surpasses the rest of the system as a bottleneck, i've noticed its mainly the hard drives on my system (mind that i'm very overclocked @ 3.8 with my ram giving me almost 9000 MB/s and fsx really isnt all that "graphically" intensive anyway) that were giving me a slow down. After installing a 6x raid 0 array though its smooth as silk almost 100 % of the time at 100% max settings (mind that before the raid array it was very smooth, even at max settings as long as you didnt try flying at 500 feet through the middle of tokyo at 800 knots in the F18)
I've got the fps locked at 10 fps in those shots because of the way tileproxy works (if you dont know what tileproxy is, its a program (( for free :D though in beta)) that downloads and loads into fsx, satelite maps from map servers such as Googe Earth and 3 others really enhancing the land class textures on fsx and fs9) At 10 fps tileproxy loads 2900 tiles/s (typical quad computer is 1200 but the raid array really helps here) where as at unlimited fps it loads about 40 tiles/s lol huge difference. Actually if fsx is running a constant 10 fps its definatly playable anyway (if your running a nvidia card though you'll want to "clamp" the "texture filtering - negative LOD bias" or anything other than unlimited will kill your fps for some reason)
Quad vs Dual? Not really sure... the way fsx works the cores is(from my understanding), core 0 does all the work, while the rest of the cores pre process the terrain. Youd think the quad would kick butt here.. BUT... the other cores have to send the info back to core 0 anyway and alot of the time that the other cores are running at 100% is time spent in loop waiting for core 0 to get back to them anyway. so a fast dual core would probly perform just as well as a quad.
Another add on that really looks like the next best thing is Flight Environment Xtreem, its a weather engine/cloud textures/water textures/runway textures/lights/(something else to do with the waters waves or something i didnt understand) program. Its going to be out "soon" (you know how that goes) but theres dozens of screen shots and previews here
--Dawn of a NEW Era-- - Flight Sim World AND (if your still enjoying fs9 instead) its also available for fs9.