I'm trying to gather some data from the MSR registers about the voltage levels at various frequency levels. I see that the MSR register: IA32_PERF_STATUS output both the current frequency and operating voltage. But the last two hexadecimal bits give the Voltage ID.

sudo modprobe msr

sudo rdmsr -d --bitfield 15:0 0x198

On one of the forums, I see that for Core2Duo you need to substitute in the following linear equation to obtain the Votlage level at a given Frequency level.

0.7125V + VID*0.0125V

and I'm using a Sandy bridge processor. Could you please direct me to a place where I can find the linear equation or help me build it.

Any help will be appreciated.