There are many many hardware versions of the S3, not all of them support variable voltage AFAIK.
@dogie and @BITMAIN can you please tell us witch versions of S3 support voltage setting? Is it depending on hardware, PIC-firmware or software?
I have two S3-B2 where hash rate always drops after some time. Both are re pasted. That helped one a bit, it stay stable for 12-24h before dropping.
I have tested all firmwares, with similar result. The 1126 firmware gave me some hope, with 0760 voltage both run somewhat stable for 24h.
But that was temporarily, they did both drop after that. And a restart, witch always have got them up to speed, did not help much. They fast dropped
down to about 350Gh/s (30-60min). Playing with voltage seemed to help a bit, but always dropping after 1h.
I tested 1219 firmware, but that was worse. Barley got over 400Gh/s.
Now I am on 1013 firmware, with my updated cgminer-monitor script that restarts when hash rate is low. That is working good.
So please inform us about different hardware, PIC-firmware and cgminer versions. I notice changes to the files in the different firmwares.
regards Tomten