OK, so you're on a budget, which I understand and can appreciate. Nevertheless, you haven't mentioned CPU overclocking, which is vital to FSX frame rate.
Also, you've selected a 7950. Are you aware that FSX, as well as X-Plane perform better with nVidia hardware and drivers?
"The following link is to X-Plane's website - http://www.x-plane.com/store/hardware/ -
and to their partner's website, XForce PC, who builds their PC's - http://xforcepc.com/store/index.php/computers.html?mode...
This is their description of their recommended hardware configuration:
"XForcePC Computer Specifically Designed for X-Plane: Intel Quad Core i5-3570K Processor overclocked at 4.0GHz, 16 Gigabytes of DDR-3 1600MHz" ... "Nvidia GTX 660 Video Card with 2GB. Requires no special adapters to run X-Plane on 3 screens."
At the time that was written, the GTX 760 wasn't released yet, however, the GTX 760 would be a better choice for FSX than the slightly more expensive 7950. Check out this review -
http://www.tomshardware.com/reviews/geforce-gtx-760-review-gk104,3542.html - where the 7950 is tested and compared with the 760, as well as several other GPU's.
Hope this helps,
Comp