I'd agree with bignastyid, the microATX AM3+ boards usually fail to support the FX-8320 or 8350. I'd definitely recommend getting a 970 or 990FX board. If the motherboard isn't failing, it more than likely will before too long.
Some other things that may be worth trying are installing these hotfixes since you're using Windows 7. These change how the scheduling and core parking features work on FX chips to improve performance.http://support.microsoft.com/kb/2645594http://support.microsoft.com/kb/2646060