I have set iStat to monitor the cpu temp only. but the difference between it and the coolbook sensor is big. iStat currently sitting on 50C, while Coolbook is only at 43C. which one should i believe. i prefer coolbook, because when i run a big cpu-demanding task. iStat says it's 109C while when i touched the machine and i'm sure it's not that hot like it's going to cook the egg.