Extreme4..hmm
try 4..and see if it takes effect..(run some kinda stresser prog..hyper-pi,ibt..prime95)
if it doesn't..use 1
One AsRock board I had..the only setting that worked was 1.
Ideally 4 is good.
Here: https://www.youtube.com/watch?v=9e04-5hjk-I