From what I've seen they mean different things for different people depending on setup. For me tmp 0, 1 and 2 are motherboard, socket (cpu heat spreader) and northbridge respectively. I'd use another program to compare such as everest home edition, believe they have a trial version. For the CPU IHS you can also run something CPU intensive and watch for which number rises and falls.
Quote from another forum:
Source:http://www.overclock.net/t/1277054/tmpin0-tmpin1-and-tmpin2-what-do-they-mean
My temps on for SYSTIN/CPUTIN/AUXTIN all read 128c max temps which i find strange but never had any problems (touch wood)