I am using Gateway NV52 (laptop) with AMD Athlon 64@ QL-65, 4GB RAM and Windows 7 64-bit with FSX and I usually get 15-20 fps with FsDreamTeam scenery, GEX scenery, FEX clouds and water, payware planes, and ASX weather.

I know that 15-20 FPS isn't too much, but my FSX is VERY smooth even when flying through clouds.

Hope it helps