This is how to undervolt 8x polaris with afterburner on new drivers

[androstan1234]

This is an odd/random/ugly workaround to undervolt up to 8 polaris gpus via afterburner on the new adrenalin drivers.

I still use AB because overdriven and claymore fail to set volts on some cards.  On other cards volts will set and stick, but only if above some threshold, sometimes 900 mV, sometimes 850.  But undervolt via offset in afterburner always works.

You must have at least one nvidia card on the rig.  Go to device manager, disable onboard gpu (intel hd 510 for me), close afterburner.  Reopen afterburner.  You should be able to control the voltage slider on polaris gpus now.  You can reenable onboard graphics.  AB voltage control works unless you close it and reopen it with integrated gpu enabled.  I usually close AB bc I don't want anything running that is unnecessary for mining.

No idea why this works exactly, but there you go.  Several of my polaris cards are undervolted to around 800 mV this way, and stable.

[DevelopmentBank]

Seems like a lot more work compared to simply using other overclocking/undervolting tools like OverdriveNtool.

I highly recommend you stay away from Afterburner if you simply want to use AMD cards. OverdriveNTool is an extremely lightweigh tool that does the overclock/undervolt process through a simple GUI without the need to go to device manager and disable anything.

[nongkrong]

Still using afterburner for overvolt / undervolt GPU?  hmmm ... please man do not use it anymore.
I did not use it anymore, after I found out that each gpu has different memory characteristics. That's how I switched to OverdriveNtool. I can set the overclock of each gpu. And I think it's safer for the durability of gpu.

[androstan1234]

I primarily use overdrive but it doesn't get the voltage as low as possible on every card.  This trick with AB always works.