The easiest and least expensive way to get better performance in FSX would probably be to just replace the processor with a Q9550.
I assume you already have an aftermarket cooler since you appear to be overclocking your current CPU. If you don't, grab one (I recommend the Sunbeamtech Core-Contact Freezer) and overclock the Q9550 as far as you feel comfortable.
I have a XFXgeforce8200socket AM2+ I have 800MzhDDR2 ram 4,000gigs. I have asparkle Geforce 9400gt 512 video card. My CPU is an AMD 5800 3.0. FSX will shut down after 10 minutes of flight. However, this shut down doesn't happen unless I am on either FSX or Tiger woods golf. The problem can't be in the CPU or it would shut down with other programs. Do I have the right hardware? Do I need to upgrade my video card? Is the problem with FSX that the hardware needed to run this program doesn't yet exist? can someone help me to solve this problem??