Hey!
I've used to have some RX 580 8gb MSI Armor Oc's laying around.
I've modded them(Bios, and overclocked) happened to get 32mh/s on ethereum with both cards no problem, settings were :
mv -96
core clock - 1240
memory clock - 2250
fan speed - 50(Can be adjusted depending on airflow and temps)
If you need help with anything let me know in my discord, I reply there faster.
Also I got the modded bios by putting in a new timing for 1:1750 and copying it to 1:2000 in the bios.
These cards underclock like a beast! I happened to get 25Mh/s for 72watt's per card(Pretty great imo when building multiple rigs in bulk)
Seems like the reason your having issues is due to overclock, and possibly a bad mod? Or just a not optimized OS, as claymore won't stay open if you have power saving features enabled, or a bad overclock. Make sure you're using these rigs for anything other than mining, and don't have bloatware on them.
Hello again!
What tools do I need to mod the bios?
Sorry totally not familiar with the process and dont want to fry the card
Thank you!