totally normal, you could update your motherboard´s BIOS, to have a look if it differs from the current one. But usually all is fine with this "auto" set voltage for your Haswell CPU.
my mb is an MSI h81m-e34, i dont see any voltage options in the bios(dont think a bios update would help either). i saw the vccin value in msi command center. thanks for the reply btw