fsx on my laptop kicks my pc's butt :)

i posted a few days ago in the x-plane forum that i was just not up to spending hours/days/weeks tweeking fsx so that it would run acceptably on my gaming pc that runs fs9 (with addons} just fine.i had dl'd the xplane demo and was impressed with the improvements so i had decided to go the xplane route and abandon fsx altogether.low and behold, on a whim i installed fsx onto my laptop (compac/amd turion 64, ati mobility 128 mg card, 1 gig ram.i expected a 2-4 fps slideshow. boy was i surprised!the default setup yeilded smooth as silk, stutter free flight with pretty bland grafics and no autogen at a locked 15 fps.panning the camera/turns was smooth also.i started moving the sliders to the right in increments, one at a time.at this point i have all sliders to the right EXCEPT autogen, water and special effects. i also have the high quality textures checked.i have autogen offi have water on 2 medspecial effects lowthe grafics are sharp beautifull and (for my taste) no autogen is needed at all. i do realize that personal tastes vary greatly.fps is still locked at 15 fps and is still smooth as silk and stutter free. i fly slow g.a. aircraft at around 1000' agl and am very happy with fsx on my laptop.but my question is, why does this laptop do so well running fsx and my 3 year old (was state of the art) gaming 'puter struggle badly?both are defragged regularly, virus free, etc, etc, etcthe laptop doesnt even come close to the pc's specs but kicks the pc's butt running fsx.anyway, i am loving fsx now and hope all of you find something that works for you.otterps: with autogen on sparse my fps drops to 10-11 fps and stutters in turns and while panning the camera. also, i have not done ANY tweeks at all. std install.