Well, thanks very nuch fotr your answers. I am not planinng on spending $4000. I was thinking on spending $1500. The thing is that i've seen all this FSX videos and they look really cool, so i want my game to perform like that.
1500 is a good number to work with but for really high performance you may need to boost that a bit (but not 3000-4000 which is just silly). Currently FSX is not a multithread game and although it does use the resources a dual core provides better than FS9 because it was written for Windows Vista, it does not need the expense of a quad core processor as listed above to make it work.
If you really want the best to make FSX run with stunning visuals and also be ready for the DX10 patch for FSX I would take the same advice I am following from someone who was a member here and was somewhat involved with FSX testing. I will be waiting until about May to start looking at hardware. The reason for that is because between now and then motherboard, memory and video card manufactures will be pushing their old technology at top dollar. If I am going to be spending a chunk of cash (and I do intend to do that this coming summer) I want to make sure what I am purchasing will not be outdated 2 months after I buy it.
The ATi R600 will in fact run circles around the 8800 and because it uses GDDR4 memory and a controller that allows the GPU to run in tandum with up to 4 other GPU's along with having the ability to take full advantage of the new motherbioard design direct access memory contollers with dual and quad core processors, it makes absolutely no sense to purchase hardware right now, especially at the price they want for some of it.
Nvidia will follow with the release of the G81. As of now less is known about the G81 than the R600 but either way, spending big bucks (even 1500) right now is money being put into last years technology.
I will be waiting until May to see what is on the market and which direction to go (ATi or Nvidia). I can either spend 1500-2500 now for last years junk or about the same in May-July for something that will take me into the next 2 years easily and run FSX better than any current hardware offered.