BIOS ver. F14d supports the FX-8370, FX-8370E and the FX-8320E.
GIGABYTE - Motherboard - Socket AM3+ - GA-990XA-UD3 (rev. 1.x)
http://www.gigabyte.us/products/product-page.aspx?pid=3901#AMD FX-8350 vs FX-8370
http://www.cpu-world.com/Compare/313/AMD_FX-Series_FX-8350_vs_AMD_FX-Series_FX-8370.html--
BTW.
After using a socket AM3 processor to update its Main BIOS to achieve support for an FX-8350 (and then testing the results for a few days), here is how I updated my GA-990XA-UD3 (rev. 1.x)'s Backup BIOS chip to match its Main BIOS chip:
1 - Use a PS/2 keyboard
2 - In BIOS, Load Fail-Safe Defaults
3 - Exit BIOS and reboot while holding down <Alt> and repeatedly tapping <F12>
4 - The following message should appear: "Press [Enter] to start copying Main BIOS to Backup BIOS..."
5 - After the Main BIOS has been copied to the Backup BIOS the following message should appear: "BIOS successfully recovered! Power off or reset system!"
6 - Switch off the power supply (or unplug its AC cord)
7 - Wait a minute or so for the voltages in the motherboard to dissipate and then clear the CMOS
8 - Turn on the power supply, boot into the BIOS utility and then Load Optimized Defaults
9 - Reboot
I have successfully employed the above steps on my current motherboard, a GA-990XA-UD3 (rev. 1.x), to equalize its Main and Backup BIOS chips to BIOS ver. F14b (which I downloaded earlier this year) thus imbuing the motherboard with native support for my FX-8350 in case the 'board's Main BIOS ever becomes corrupted due to a malware attack etc and the GA-990XA-UD3 (rev. 1.x) has to boot into its Backup BIOS to repair its Main BIOS.