SUPPORT FOR THE FX8320 and FX8350 ON THIS BOARD (ASRock 990FX Extreme3) was pulled due to thermal issues , they are not supported.
Here is the support list for the board.
AM3+ Opteron OS3320SJW4KHK 25W Piledriver 1900MHz 1400MHz 2MBx2 8MB C0 P1.40
AM3+ Opteron OS3380OLW8KHK 65W Bulldozer 2600MHz 2000MHz 2MBx4 8MB C0 P1.40
AM3+ Opteron OS3280OLW8KGU 65W Bulldozer 2400MHz 2600MHz 2MBx4 8MB B2 P1.40
AM3+ FX FD8300WMW8KHK 95W Piledriver 3300MHz 2200MHz 2MBx4 8MB C0 P1.30
AM3+* FX FD8150FRW8KGU(BE) 125W Bulldozer 3600MHz 2200MHz 2MBx4 8MB B2 All
AM3+ FX FD8140WMW8KGU 95W Bulldozer 3200MHz 2200MHz 2MBx4 8MB B2 P1.20
AM3+ FX FD8120WMW8KGU(BE) 95W Bulldozer 3100MHz 2200MHz 2MBx4 8MB B2 All
AM3+ FX FD8100WMW8KGU(BE) 95W Bulldozer 2800MHz 2000MHz 2MBx4 8MB B2 All
AM3+ FX FD6350FRW6KHK 125W Piledriver 3900MHz 2200MHz 2MBx3 8MB C0 P1.30
AM3+ FX FD6300WMW6KHK 95W Piledriver 3500MHz 2000MHz 2MBx3 8MB C0 P1.40
AM3+ FX FD6200FRW6KGU 125W Bulldozer 3800MHz 2200MHz 2MBx3 8MB B2 P1.20
AM3+ FX FD6130FRW6KGU 125W Bulldozer 3600MHz 2200MHz 2MBx3 8MB B2 P1.20
AM3+ FX FD6120WMW6KGU 95W Bulldozer 3500MHz 2000MHz 2MBx3 8MB B2 P1.20
AM3+ FX FD6100WMW6KGU(BE) 95W Bulldozer 3300MHz 2000MHz 2MBx3 8MB B2 All
AM3+ FX FD4350FRW4KHK 125W Piledriver 4200MHz 2200MHz 2MBx2 8MB C0 P1.30
AM3+ FX FD4320WMW4MHK 95W Piledriver 4000MHz 2000MHz 2MBx2 4MB C0 P1.30
AM3+ FX FD4300WMW4MHK 95W Piledriver 3800MHz 2000MHz 2MBx2 4MB C0 P1.30
AM3+ FX FD4200FRW4KGU 125W Bulldozer 3300MHz 2200MHz 2MBx2 8MB B2 P1.20
AM3+ FX FD4170FRW4KGU(BE) 125W Bulldozer 4200MHz 2200MHz 2MBx2 8MB B2 All
AM3+ FX FD4150WMW4KGU 95W Bulldozer 3900MHz 2000MHz 2MBx2 8MB B2 P1.20
AM3+ FX FD4130FRW4MGU 125W Bulldozer 3800MHz 2000MHz 2MBx2 4MB B2 P1.20
AM3+ FX FD4100WMW4KGU(BE) 95W Bulldozer 3600MHz 2000MHz 2MBx2 8MB B2 All