I am powering a mobo (Asrock H110 Pro BTC+) with a 1200w power supply. The board is hosting 10 GTX 1060 6gb. In 1bash I limit the consumption to 80W per card.
Whenever I add an 11th card, the system becomes very unstable, rebooting after few minutes Ethminer is running.
I tried to swap cards, risers and slots without finding a solution.
I believe it's a power problem, nevertheless the 11 cards system absorb a total of 910w, that is still within the limits of the power supply.
Any ideas on how I can diagnose the problem?
It is a power problem. Even though your PS is listed as 1200W you have to account for efficiency and power loss. A premium Platinum rated power supply has an efficiency of 93-95%, Gold has 86-90% while Bronze rated power supply has 80-85% efficiency, the rest is dissipated in heat.
When you add consumption from the motherboard, CPU, HDD or SSD you are running your PS at its limit, hence the instability and random reboots. Since we are running these power supplies 24/7 I recommend using Platinum power supplies and load them no more than 85%. They cost a bit more but they'll pay off due to power savings.
On a side note, I also use 1060's mining ETH. I have them set at 75W and seen no significant improvement if I increase over 75W. Try lowering yours to 75W, it might save enough juice for your 11th card without restarting.
Thanks for your answer.
I lowered to power to 75W per card, but the system is still rather unstable.
The power supply that I have is a Corsair HX1200i . It's rated Platinum. I was hoping to use the integrated Corsair link to diagnose these kind of problems but there are no drivers for linux.
Now, I am faced with two options:
1) buy an extra smaller power supply to complement the existing one, for example an HX850
2) leave it as a 10 GPU rig and start afresh with a new rig
Option 1 would be slightly more cost effective, but I never assembled a rig with two power supplies and I am concerned with possible power loops.
What do you think?