So, could you guys post ur hashrate and temperatures?
I'm pretty sure you get lower hashrates if your temps are below 45-50C.
At the moment, some of my S7's are getting cooled by direct -17C outdoor air, which keeps the temp on the boards at 33C (Thats what the sensor says anyway.., not sure if this is accurate when getting blasted by -17C air). The hashrate avg is 4.7TH/s @ 625Mhz
Some other S7's are "cooled" with indoor air, which keeps the temp on the boards at 65-70C, these are hashing at 4.99TH/s avg. @ 625Mhz.
The ones cooled by outdoor air used to hash at 4.99TH/s as well.
Conclusion:
Board temps below 45-50C = Bad? ^^
I have found it to be generally true that all of my antminers (going back to at least S3 is when I first noticed it) get better hashrates at higher temps (to a point). And what I mean by "higher" is also model specific. I remember setting some of the S3's so that the hot air coming out of the PSU was directed at the intake on the miner because it improved the hashrate slightly when they were running in a room that was 60-65 °F ambient. I should maybe also point out that on my S3's I had removed the blue fan wire so they ran at 100% fan speed all the time as well. I have an S5 located in a basement crawlspace (that has vent opening to the outside) that gets lower hashrates now that it is winter and the ambient temp is lower where it is. I am not sure what the optimal temps on the S7's are yet but looks to me so far like in the 60's as reported by the GUI is where I am having best results.