i'm running 12 x 6990 at the absolute edge in overclocking mode (power, temp) - they are all running at 100% 24/7 - unfortunately i have to clock down if the ambient temp is rising, but i use a script for that - a few pic: http://imgur.com/a/usqDL
I love this pic http://i.imgur.com/fevHc.jpg
Would you care to share your script(s) or how you show temperatures and the last picture where it shows V (is that volts?)?
sorry for the OT
the bash script for the autom. clock control (based on temp) is from the forum here, but i don't have the thread in mind, you may try the forum search function
the lower terminal windows are the output of lm-sensors (took me 2 days to fix all the kernel and driver stuff :-( ) - important for me is that temp sensor, it give me some estimate about the ambient (server room) temperature - the A/C is a old lady already
the V - yes that are Volts, since there is nowhere a hwmon for the 12V, i use the 3.3 V reference as a guessing - in idle it is around 3.3, below 3.10 the motherboard or the cards crashing frequently, so it is a good guess ;-)