So I have managed to reach a bus speed of 250BCLK on my ASUS Maximus Impact VIII with 6700k cpu. :nerd:
had to set these values:
1) PLL Termination Voltage 1.5v
2) Level 7 PLL Bandwidth
3) PCH core 1.2v
it is awesome figures to look at having Bus speed running that high while your cpu and ram run high too!
CPU @ 4.5ghz
Multi 18x
RAM @ 3000 mhz
Bus speed @ 250 mhz
here is screenshots