I dont know how accurate but.. I have 3 CUSL2, using 2 850 and 1 933 cpus and two of them read 41 on the same heatsink but one reads 61, even with dual fan on the heatsink, it still reads 61, so my sensor could be shot for one of them...
All I know is the cpu is way too cool with two of those delta fans and don't think it can get cooler...