Heliox - just to update that I managed to get the -175mV working on the new batch of Nanos.
I have not got all 6 cards in a complete setup yet, but testing on 1 card is a success.
I will run it overnight before flashing the other cards.
I will report the kill-lo-watt meter readings tomorrow morning.
As of now, with -175mV rom:
-6mV,1040/300 = 30.3MHs at fans= fix 60%, temps 67-68c
and
stock -175mV,800/300 = 22.4MHs, temps 62-63c, auto fans
I am tempted to try the -200mV rom.
Is it normal that some rigs will have 150 roms and some 175 roms, mixed configs in your environment?
It is very normal. I have nano accepting the -200, 175, 150 and 125. That is depending on your luck.
I had no luck with Nanos I bought from Amazon - best was only the -150mV working, not the 175 and 200 mods
But this new batch seems to be ok - I was surprised to get it to 32MHs -100mV, 1040, 300 without the rom mod.
With the mod, I am getting 30MHs -150mV,1040,300 with lower watts and amps - which I need because electricity is expensive in my country.
My XFX Nano was from Amazon and it's working good with -175mV.