Beware of people telling you that you will never get good fps unless you have an ultimate cpu/gpu combo
Some places try to charge you about £1500/$2500 for a good fsx pc.
On my current system, i get 45fps with high settings and full ai traffic
AMD Phenom II X4 970
ATi Radeon HD5670 512mb
Pegatron Narra 6 M2N68-LA Mobo
4gb DDR3 1066MHZ Ram
OCZ StealthXStream 400w PSU
92mm Blue LED Fan
for about £450 incl Antec 300 and DVD Drive and HDD @500gb
Good planning and building will ALWAYS beat a pre-configured deal... But 70% of those end users call the computer case the hard drive, and it's not false info to sell something that will play or do what the purchaser wants! In the end, it's customer satisfaction that's the bottom line... That and follow up support!
"Ultimate CPU/GPU combo"? Of course that's not needed, but having good parts helps. You have one of the best quad core CPUs that AMD makes. FSX needs CPU power so of course you'll do alright. Ever see anyone try to play it with a lower end dual core? How is it false if you bought one of the best?
The 5670 isn't a bad GPU either. I'm guessing your playing at 1440x900, or 1680x1050. I'll call BS if you have the 5670 doing that at 1080.