first you need to make sure the motherboard supports the cpu some did get a new bios for newer chips some may not or did not ?
example
check cpu list to see if the cpu you want to use is listed
then see what bios supports that chip
''2011-3 Xeon E5-2689 v4(B0) Broadwell-EP 3.1GHz BLK 100MHz 25MB 165W P3.30 ''
so for it bios needed is P3.30 check bios download page and see there now 3 newer bios you can use over 3.30 that will work as well
http://www.asrock.com/mb/Intel/X99%20Extreme4/?cat=Download&os=BIOS
down load the file to a folder you made on your desktop [opinion]
click the how to update icon with the corresponding bios you selected
http://www.asrock.com/support/BIOSUI.asp?cat=BIOS8
or refer to your boards manual on its how to ..
I prefer manual updating with a usb pen drive [Method 2:] over auto updating or through windows program cause it can fail at any time wile ''on line '' like a cut disrupted connection wile flashing ??
get the file down loaded and check it
http://www.asrock.com/mb/Intel/X99%20Extreme4/?cat=CPU
asus example
https://www.asus.com/us/Motherboards/X99DELUXE/HelpDesk_CPU/
https://www.asus.com/us/Motherboards/X99DELUXE/HelpDesk_Download/
https://www.asus.com/us/support/FAQ/1012815/
just check your motherboard manufacture bios flashing process / support for your board
bios flashing is easy but its still one of the biggest risks of maintaineance and can easy brick a motherboard if something goes wrong