example for the 5.6 chip
boots 56x100, doesnt not boot 57x100 (blinking command prompt equals your max multi for the amount of cores you are using) so then you increase bclk till you cant any more so 56x101.1 then in OS it will go up to 56x101.3 etc
I like the gd65 revster, just make sure you have some good non-hyper sticks