What's the difference between "aux voltage" and "cpu core voltage?"

[iLoveDivX]

I have an 8rda+ and i set the cpu voltage to 1.85. but sisoft reads my core as 1.57 and my "aux voltage" as 1.89. my black bios screen reads my core as 1.88. what exactly is the aux and is there anything wrong with my comp?

 

[iLoveDivX]

^

 

[BmXStuD]

search yahoo duh ;0