What's the best -h value for 4/580?
It really depends on how hard you want to push the card / what the extra power consumption is worth to you. I'm running:
-a 4
-h 1920
-cvddc 850
-mvddc 850
-cclock 1150
-mclock 2250
Average Hashrate for last 6 hours: 2,963.3 H/s (or ~493.9 H/s per card)
Runs about 80-85w/card and maxes out around 779w total from the wall (total rig - 6 RX580's, 1000wPSU + 850wPSU). Temp 45 (fan 60%),
I'm kinda curious what the flags are to get 700+ H/s though?!
My rx 470 are doing much better. Something is wrong with your settings.
724 H/s @ <80W from the wall average per card from 12x rx 470 nitro (non-plus), using sgminer-gm. Modded bios - Samsung memory 1750 -> 2000 straps (last PBE can't recognize the memory and there are better mixed straps I suppose). Memory @ 1950-1980, GPU clock @ 1169, both downvolted using AB (-96) and Wattool (additional core downvolt and memory @ 870 (two of the cards are @ 900 or they are not stable - they were stable at 870 too, but I'm not sure what happened). 63C @ 35% fan, stable, <0.4% rejected, no HW errors. It goes to 740+ average stable, but with 15-20% more power and <1% rejects. I didn't tried the blockchain drivers yet.