Cpu Core Voltage

[Joe-912]

Hi all, when stress testing with XTU I get a variations in cpu core voltage, from CPUZ it's 1.15v XTU it's 1.1530-1.156v and AI Suite3 it's 1.168v, Which one is right it's only a slight variation but just wondered which you think is right.
Asus Maximus Hero VII
4790K @ Stock
G-skill Sniper 2133
Cooler Master v850
All settings in Bios on auto, memory manually set on 1.53v
Windows 7 64bit
Gigabtye GTX 970 G1


Memory set on XMP

Thanks much
Joe