Ive wandered about this as well, i use coretemp for temperature readings and also have hw monitor and asus pc probe2, hw monitor lists, SYSTIN TEMPERATURE 25'c and pc probe lists mb as 25'c, i assume theese are the same reading, also i take it this isnt the NB chip reading, although i used a temp probe on my NB heatsink once and it was reading 30'c.