amdgpu-pro 17.40 is a disaster, at least on my 16.04.3 machine.
Hi, I've got 9x MSI Armor RX580 8G recently. The cards by itself not really great maybe because of Hynix memory.
I was able to tune them from 21Mhs ETH stock (single mode) to 29.5/930 ETH/Dcr (dual-mode) under Win10, 110/75W GpuChip/GpuCore, 1500W from the wall for 8x cards and 1200W in single mode. The problem with Win10 and Blockchain driver I can't really change the core voltage, whatever I set in bios, the driver sets it to 931, and most importantly Win10 doesn't boot with 9th card.
Anyways, I gave a try to Ubuntu 16.04.2 TLS and the latest AMDGPU-PRO Driver for Linux 17.40 and setup everything as per their manual.
a) It boots with 7xGPUs but with 8x I get 'the system is running in low-graphics mode' and nothing really helps.
b) It gives 23Mhs ETH for a single mode and draws 110/130W, around 250W per GPU, which is really bad. Setting the voltages int Claymore looks like doesn't work, it draws the same from the wall.
Is the previous driver 17.30 better then 17.40?
Are you able to mine on Linux with similar results (+-1/Mgh) as in Win 10? If yes, what drivers do you use, how do you undervolt, any information will be much appreciated.