Core voltage

V core, or core voltage, is the voltage supplied to the processor core. While some microprocessors require specific core voltage, other may specify their core core voltage as a range of values. When the core voltage values specified as a range, it means that the manufacturer may configure the CPU to use any voltage within the range (it's actually more difficult than that - the range contains fixed number of voltage values, and the CPU may be configured to use any one of them). Core voltage may not be the only voltage required by the CPU. First microprocessors often required multiple voltages. For example, 8080 microprocessors required three different voltages: -5 Volt, +5 Volt and +12 Volt. More modern CPUs used different voltages for the core and I/O system.

Care should be taken when setting core voltage on motherboards where core voltage value can be set manually. Setting the voltage lower than required may result in CPU instability or the CPU may not be able to turn on at all. Exceeding maximum core voltage value may cause CPU instability or even permanently damage the CPU.