Which cpu temp should i trust?

I am running a new phenom ii BE in a new build (built it like 2 weeks ago just got processer last night, was going to wait for bulldozer but couldnt). i have it overclocked to 3.8, stable for 10 hours under prime 95 so far. i had HW monitor open, which tells me my core temps are 50, max was 52. i didnt run amd overdrive with it, but the core temps it gives me with that are always the same temps as the 1s it gives me in tmpin2 in cpuid, it said that it maxed out at 80. running cooler master hyper 212+ with that heat sink grease, theres no way this last temp can be right. and is it normal that my cores never vary from each other more than like 1 degree farenheit? the celcius temps never vary, cus its less that a degree C.