My 12 GPU rig (7 x RX580's, 4 x RX480's and 1 RX570) is running stable since v11.2.
Rig was doing 359 Mh/s before v11.2, stale shares 5-10%.
on v11.4, same oc, 366 Mh/s, proved stable, but the effective average hashrate on ethermine was 5-8% below reported, stale shares 5-10%.
Upgraded to v11.4 and started testing different oc's. Increased cclock to 1200 from 1175, and decreased mclock to 2180 from 2200. Same ratio of oc for RX570 as well (cclock to 1100, mclock to 1930)
Rig is running 362.6 Mh/s stable, average effective hashrate is 3% below reported, taking in mind that fees are 2%, and 0-3% stale shares.
Rig is running on SMOS.
Only mining ETH.
Auto detection of DCRI
All cards are bios-modded
140w on avg for each card from the wall (undervolting doesn't play well with Linux)
Miner Console
ETH: GPU0 30.206 Mh/s, GPU1 30.524 Mh/s, GPU2 30.506 Mh/s, GPU3 30.524 Mh/s, GPU4 30.525 Mh/s, GPU5 30.447 Mh/s, GPU6 30.228 Mh/s, GPU7 30.496 Mh/s, GPU8 30.526 Mh/s,
GPU9 30.219 Mh/s, GPU10 30.227 Mh/s, GPU11 28.236 Mh/s
ETH: 03/15/18-10:42:44 - New job from eu1.ethermine.org:4444
ETH - Total Speed: 362.665 Mh/s, Total Shares: 418, Rejected: 0, Time: 01:21
Hope it helps