Quote from: canford on December 21, 2014, 11:37:07 PM

Quote from: canford on December 21, 2014, 08:55:29 PM

Quote from: IITravel01 on December 21, 2014, 05:33:39 PM

Quote from: canford on December 21, 2014, 10:18:31 AM

I continue to find this extremely frustrating. I am running 6 S3+ units, each supplied by a 750-800W power supply with a single 12V rail and all four PCI-E connectors connected. I tried the 275/0815 settings, and exactly the same thing happened as the last time. Hour 1: fantastic, all units over 500 GH/s, holy crap why did I not do this earlier. Hour 2: OK, but hashrates down both as reported by units and at the pool. Hour 3: terrible, all hashrates reported by units and by pool way below stock results. So I have yet again reverted everything to 225/231/243/237/225/237 with voltage left blank.

I do not understand the mechanism here. If it is heat, why does it take 2 hours to show up? With the OC settings, all chips show up as "o" and working. But the hashrate results speak for themselves. But why the very prominent jump in hashrate for the first hour, but then utter crap out in hour 3? Can anybody explain this?

Which firmware are you using?

I am using the 1024 firmware, the only change on top of that is adding the new frequencies into cgminer.lua. All six units stable again at the lower frequencies with no voltage setting.

Trying again on one unit, this time with ckolivas's S3 cgminer 4.6.1 build, also deleting --queue and adding --lowmem. I can't think of anything else to try. The S3's are in a ventilated space, so the ambient temperature over the three hour period is constant. Why would I get great results for 1+ hours, but poor results over 3 hours?