Current state :
8x Sapphire RX580 Nitro+ Special Edition (blue one) - Samsung mem + Uber-mix v 3.1 straps flashed silent bios
Aug23 blockchain drivers
-cclock 1150;-mclock 2125;-cvddc 880;-mvddc 880;
power drain - ~1380W+/-20W measured on wall (idle system 150W)
miner without restarts - minimum GPU memory errors
~ 245MHs
Still digging around to lower electricity drainage..
Did you try Uber-mix v.2.3 straps? They looks more stable and even less mem errors than v.3.1 at my ASUS RX480 DUAL cards with Samsung memory