There is always one core hotter than the other, the same goes to some Sandy bridge CPUs aswell.
Heck I have seen temperatures just like this with stock cooler on the 2nd generation Intel® Core™ processors. The reason for this extra heat is that the core is in the middle and so it gets heat from the first core and then when it starts to run it generates its own heat, giving that core a higher overall temperature.
is this normal for this reading? got the same temps on my 3470 also on a under load no gaming, using also the same aftermarket heatsink
Yes its normal.
got this temp earlier today using prime95 for about 18 minutes or so, so is this still perfectly normal temps?
Probably, the cooler you have is only rated at 120W. Still well within tolerances.
Regarding the 10 degrees difference, I looked at my 3470 and got 30 30 20 30. So despite the overall temp being lower (i30 cooler is rated at 320W) there is still a 10 degree variance.
what does it means that my cooler only have a 120w rating? I'm sorry to ask i have no idea about this.. thanks
It means that the cooler only will dissipate 120 Watts of heat. The TDP of the i5 3470 is 73 Watts, so that cooler should be adequate.
okay thanks man, so how about his temps after using prime95 for 18 minutes, is it still normal? no worries? it hits 59c on the package core
Those temps are safe. Intel specs say that 72 celsius and higher are what aren't safe for long term operation.