Both normal firmware and bertmod are using data from lm75 temp sensors (chip in red circle in the picture below). One sensor is on each mining board and one is on controller board. Differences are probably caused by refresh rate of the temp data. Stock firmware refreshes data each minute, stores them to /var/run/stats.knc and displays this file. Bertmod refreshes when requested.
Unfortunately, there is no way how to get temperature from VRMs (or at least I did not found it in datasheet)
http://i.imgur.com/HFZZ6t9.jpgAwesome! There is temp data available if the VRM is the 'digital' version, the details are on page 16 of the
datasheet. After a close read, it does seem you are indeed correct, that the PMBus will only report two temperature 'flags' OT_WARN and OT_FAULT, not actual temperature
data. The location of the lm75 makes sense why it seems to track the DC/DC module (PCB) temperatures better than reporting accurately for the ASIC itself.
Exactly. And it also seems that these limits are hardwired into VRM (so no way of lowering them and checking warn flags to get at least approximate temp value).
