As you can see by looking at them, the boards are splitted in 2 halfs, each half having a separate power module (1 module for 16 hash chips) so when modifing R1_1, same modification is needed for R1_2 as they have the same values. The same goes for R2_1 and R2_2.
Zeus chips can operate from 0.8 volts for Vcore upwards ( I did not try to overvolt, so max value unknown).
The interesting thing for me is that these chip can be undervolted/underclocked to require only 3 amp/blade (12-13amp/1complete unit + fans) while hashing at about 2.8-3Mh/s per blade or 11-12Mh/s per unit. This would mean a power requirement of about 13watts for 1Mh/s at minimum as oposed to over 30 watts/Mh from factory.
Also, the generated heat would be almost neglijable at these settings. Probably only using one of the units fans would be enough.
If a modding and/or service tutorial would be usefull for you, please let me know.
Thanks for sharing that. I have a thunder x6 i would like to oc and take to the max.....i just need some help with it. So if you have a tutorial i'd be more then happy