We are able to achieve a 29-30 MH/s Hash Rate using the MSI RX 580 Armor 8GB OC Graphics Card with the PolarisOneClick BIOS Editor with the following settings:
We are using the ethOSDistro Operating System for our RX 580 Ethereum Mining Rig. Here are the statistics.
Number of rigs: 4
Total Hash Rate: 820 MH/s
Total Power: 793 + 702 + 684 + 670 = 2849 Watts

Ethos stats for the rig running at 670 Watts
driver: amdgpu
gpus: 7
fanrpm: 3426 3460 3391 3402 3467 3350 3331
fanpercent: 73 73 73 73 73 73 73
hash: 204.43
miner: ethminer
miner_hashes: 29.21 29.20 29.25 29.24 29.10 29.22 29.21
models: 01 Ellesmere RX 580
02 Ellesmere RX 580
03 Ellesmere RX 580
05 Ellesmere RX 580
06 Ellesmere RX 580
07 Ellesmere RX 580
08 Ellesmere RX 580
default_core: 1366 1366 1366 1366 1366 1366 1366
default_mem: 2000 2000 2000 2000 2000 2000 2000
vramsize: 8 8 8 8 8 8 8
core: 1100 1100 1100 1100 1100 1100 1100
mem: 2140 2140 2140 2140 2140 2140 2140
memstates: 2 2 2 2 2 2 2
voltage: 0.855 0.837 0.853 0.833 0.833 0.836 0.834
default_watts: 175 175 175 175 175 175 175
watts: 91 91 88 87 89 89 85
watt_min: 30.00 30.00 30.00 30.00 30.00 30.00 30.00
watt_max: 205 205 205 205 205 205 205
powertune: 5 5 5 5 5 5 5
Ethos stats for the bottom rig running at 702 Watts
driver: amdgpu
gpus: 7
fanrpm: 4396 4472 4451 4454 4329 4386 4349
fanpercent: 100 100 100 100 100 100 100
hash: 206.1
miner: ethminer
miner_hashes: 29.52 29.53 29.52 28.98 29.51 29.51 29.53
models: 01 Ellesmere RX 580 xxx-xxx-xxxx Micron
02 Ellesmere RX 580 xxx-xxx-xxxx Micron
03 Ellesmere RX 580 xxx-xxx-xxxx Micron
05 Ellesmere RX 580 xxx-xxx-xxxx Samsung
06 Ellesmere RX 580 xxx-xxx-xxxx Micron
07 Ellesmere RX 580 xxx-xxx-xxxx Micron
08 Ellesmere RX 580 xxx-xxx-xxxx Micron
bioses: xxx-xxx-xxxx xxx-xxx-xxxx xxx-xxx-xxxx xxx-xxx-xxxx xxx-xxx-xxxx xxx-xxx-xxxx xxx-xxx-xxxx
default_core: 1366 1366 1366 1366 1366 1366 1366
default_mem: 2000 2000 2000 2000 2000 2000 2000
vramsize: 8 8 8 8 8 8 8
core: 1100 1100 1100 1200 1100 1100 1100
mem: 2140 2140 2140 2000 2140 2140 2140
memstates: 2 2 2 2 2 2 2
meminfo: GPU0:01.00.0:Radeon RX 580:xxx-xxx-xxxx:Micron MT51J256M32:GDDR5:Polaris10
GPU1:02.00.0:Radeon RX 580:xxx-xxx-xxxx:Micron MT51J256M32:GDDR5:Polaris10
GPU2:03.00.0:Radeon RX 580:xxx-xxx-xxxx:Micron MT51J256M32:GDDR5:Polaris10
GPU3:05.00.0:Radeon RX 580:xxx-xxx-xxxx:Samsung K4G80325FB:GDDR5:Polaris10
GPU4:06.00.0:Radeon RX 580:xxx-xxx-xxxx:Micron MT51J256M32:GDDR5:Polaris10
GPU5:07.00.0:Radeon RX 580:xxx-xxx-xxxx:Micron MT51J256M32:GDDR5:Polaris10
GPU6:08.00.0:Radeon RX 580:xxx-xxx-xxxx:Micron MT51J256M32:GDDR5:Polaris10
voltage: 0.858 0.860 0.858 0.935 0.862 0.891 0.861
default_watts: 175 175 175 175 175 175 175
watts: 91 89 91 105 92 97 92
watt_min: 30.00 30.00 30.00 30.00 30.00 30.00 30.00
watt_max: 205 205 205 205 205 205 205
throttled: 1
powertune: 5 5 5 5 5 5 5
ethOS config:
#Ethereum
maxgputemp 75
stratumproxy miner
proxywallet 0x9d8370ec365d2b51261365cb6017540d5de8f567
proxypool1 pool-usa.ethosdistro.com:5001
proxypool2 pool-eu.ethosdistro.com:5001
flags --cl-global-work 8192 --farm-recheck 200
globalfan 75
safevolt disabled
cor 4da0e4 1100 1100 1100 1100 1100 1100 1100
mem 4da0e4 2140 2140 2140 2140 2140 2140 2140
vlt 4da0e4 840 820 840 820 820 820 820
You will notice that 2 of the GPUs are set to 840 vlt. This was to improve stability as these 2 cards failed after 2-3 days on 820 vlt setting. Upping the vlt by 20 for these 2 GPUs improved the stability and they now run 24/7 with no failure or requirement for rig reboot.
Hash rates varied from between 29.2 MH/s - 31 Mh/s.
Hope this help those running an RX 580 Mining Rig
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