Overclock your mem's / underclock your GPU's , with proper undervolting , and enjoy mining with full speed
Would you like to share your settings with us? What does "proper undervolting" mean?
With proper undervolting he means that you should not only decrease the power to 80 or 70% but that you should the decrease the voltage from the GPU from 1 to 0.95 for instance.
I highly suggest you to find a decent clock and voltage for your gpu and then use polaris bios editor to edit fan speeds and clocks , then apply them to your entire rig.