well i found my own answer in coretemp help faq's..........
VID is not the same as VCore. VCore is the actual voltage the processor is being fed by the motherboard.
VID is the recommended voltage the processor should be running at at the current power state, this is a predetermined value, programmed by the CPU manufacturer. When the processor settings, especially the VCore is kept at default settings, Core Temp will provide a good approximation of the real VCore, but if you change the setting using the BIOS or by other means, Core Temp's VID readings should be ignored.