I have solved my stability problem. Miner (PC) would often freeze and stop responding. Sometimes after 3h, but never more than 24h of run time.
And the solution is:

• Update motherboard BIOS and configure it like this:
• DMI Max Link Speed => Gen2
• PCIEX16 slot's Link Speed => Gen2
• M.2 slot's Configuration => PCIE mode (if you have M.2 slot risers)
• Above 4G Decoding => Enable (if using more than 4 GPU's)

It is very important to set PCIE and M.2 speed to Gen2. Don't live it to Auto!

Using 8 EVGA 1070 and getting 3302 sol/s @ 900W of power usage (about 420 sol/s per GPU)
Power limit 50%
Core Clock +150MHz (1657MHz)
Mem Clock +0 (3802MHz)


Best luck to all