I'm having issues with undervolting, if I set the core voltage lower before starting the miner it crashes the whole system, if I do it after starting the miner it's solid until there's a disconnect/ reconnect for whatever reason, any workarounds for this? Maybe set a high power limit? Thanks.
Are you using a 290/290x/390/390x by any chance, they crash to a blank screen when undervolting? Maybe Nano, I've never used a Nano though.
I had the same issue. The problem with undervolting these chips using something like MSI AB is that the voltage adjustment is an offset and applied across all states(7 different DPMs). While I found all my cards would happily run with a -100mv adjustment at full load(DPM7), even at 1050MHz core, as soon as they went idle they would crash.
Why? This is because the offset is applied to the other DPM states of the core across the frequency range, and presumably the core isn't stable at these other states with the -100mv offset also applied.
I fixed the problem though! I went here
http://www.overclock.net/t/1561372/hawaii-bios-editing-290-290x-295x2-390-390x and read about editing the BIOS.
I ended up setting custom voltages and frequencies for the 8 different states so I no longer need to set a negative offset in any software. Now I can run them at full load, at 1050MHz core, stable, with less than 1.1v. And they don't crash as soon as the miner stops running, because voltages for the other states are still high enough for stable operation.
I can provide an example BIOS if you want? I did it for my ASUS, XFX and 2 MSI 290x cards. Fixed the issue for all of them.