If you go in BIOS and set vtt to 1.20, your ref will say (if not on auto) what ET6 has. But as you increase vtt the refs scale up in ratio. That's why ET6 still shows them at stock values. Set your vtt to 1.2 and then change your refs to what sergio says. Then bump up vtt to desired value (you shouldn't need 1.5 either!) and refs will scale with it. ET6 will then show the ref values you set at vtt 1.20.