For an old man, I think I made pretty good progress in the past week. Sorry if I ask stupid questions. Working with (4) Gigabyte RX580 Gaming 8GB that have Hynix memory. With geth/ethminer in linux I was getting ~20mh/s each GPU, stock vbios.
Reading here, I learned how to flash vbios. I used latest atiWinflash for saving factory roms, and latest polaris bios editor for writing new roms. Found some settings here and anorak that helped boost hash rates. Windows drivers also helped. Stock vbios in the cards on Win10, now I get ~23 mh/s each. Upgrade to AMD Blockchain drivers for Win10, now each card 25 mh/s.
Flash vbios with some magic "timing straps" whatever the hell that is, and now I get 28.3 mh/s each card.
One out of four cards, I made a brick but learned to unbrick it , and back in bizness. :-) To all persons who share knowledge here, thank you.
Saved my ass! :-D
Now stupid questions about reducing power yet maintaining hash rate. I get that each card is different. I kinda get how the bios changes can improve power consumption, but not really.. Using gpu-z tool, gpu power consumption figures when mining look like this; (one card at a time for bios tweaking and testing).
Now that all cards are flashed with custom timing straps, hash rates are within 0.5 between cards. But power draw obviously is not. I am very happy to have gained 8mh/s per card by drivers and vbios flashing. But I don't really know what I'm doing, and don't have experience with mining. Is it normal to have that much power variance between cards? Starting points for tweaking: GPU core clock: 1350 Mem clock: 2200 undervolt mem to 950 - all these done in vbios that is flashed onto card.
Sorry I cannot seem to use AMD Settings "WattMan" for the undervolting, the app does not seem to recognize mouse click or I just don't get how to change settings using that software..
I have not messed with claymore volts features yet. I *have* messed with claymore fan control, and it seems to work ok. No over heat probs so far, temps ~65C.
Any suggestions on reducing power without hurting mh/s are super appreciated. Thanks again to all who share how to do this crazy stuff.