GPU mining question from noob: I have 3 RX580's on a 750W gold PSU times 2 (6 cards on two 750W PSU's). This is my first rig and I am having an issue with the system shutting down within 10 minutes of hashing. I believe it is because the GPU's are drawing too much power. So, how do I undervolt the cards so that each card is pulling less than 150W? Thanks.
Note: I am keeping the temp's on each card under 75C with 6 high power fans.