CPU core voltage

As the core voltage or Vcore and Core Voltage is referred to in the electronics and information technology, a supply voltage of an integrated circuit (eg, a microprocessor ). The term is used to distinguish if a different supply voltage to the communication with the external world are in a block, the latter being referred to as the I / O voltage.

The technical background is the independent determination of one hand, the supply voltage of the actual inner life (eg, the eponymous processor core ), which is a key parameter for the maximum clock rate ( speed), but also the power dissipation ( heat) of the block, and on the other hand, the voltage for the I / O ports, which determines the signal voltages to the module ports and thus ensures compatibility with other connected devices. Part of the I / O circuit of the block are level converters which convert the signal voltages between the core voltage level and the I / O voltage level. By the separation of the two supply voltages are relatively low core voltage is possible, which is a prerequisite for the efficiency of, for example, modern microprocessors or FPGA. Furthermore, it is possible to design the core of variable voltage, to adjust their depth changing demand for processing power. ( As an example, here is the increase in the battery life of a mobile phone or a laptop called. )

Analogous to this separation between the core and the outside world, different parts of the system within a block (eg CPU core, memory and peripheral areas of a microcontroller ) with adapted each to their needs supply voltage can be operated so that such a block then three or more voltages required for operation. This need not even be of different heights - often there is the separation only to switch off individual function blocks independently of the others can. Another reason for separate supply of individual function blocks is to reduce the mutual interference - common in analog -to-digital or digital - to-analog converters as separate supplies for the analog and the digital part. In this context, however, one does not speak of nuclear power.

Details

The height of the core voltage is specified by the manufacturer. In this case, the power supply is specified, which must be complied with a specified tolerance. Alternatively, it can also specify a range, possibly also depending on other parameters ( eg ambient temperature, clock speed ).

Difficulty in providing for example, a processor is that the current consumption varies greatly in a short time (up to several hundred amperes per microsecond). Appropriate measures (eg buffer capacitors) it must resulting voltage fluctuations are absorbed, so that the core voltage within the specified (tolerance ) range remains. Otherwise, a more stable operation of the processor can generally not be guaranteed.

During the optimization on the lowest possible consumption of nuclear power has an important role: Many CPU architectures today are able to adapt, frequency and voltage during operation on the utilization of functional units ( see undervolting ). This has a positive impact on energy consumption and - indirectly - on the heat loss. Especially with mobile devices, this leads to a longer duration, or the devices come with smaller, lighter power sources ( batteries ) from.

Since stability and efficiency of a CPU is heavily dependent upon the quality of the power supply, the manufacturers strict guidelines for voltages, tolerances and other characteristics (eg, type and number of energy-saving mechanisms ) out. For current CPUs with x86 architecture this example in the ATX12V specification ( → ATX format) are recorded.

Recent developments show that the term " core voltage " in the future could no longer be true: A further improvement of energy efficiency is the independent supply of the individual functional units of a CPU with the respective optimal clock frequency and voltage. A core voltage in the classical sense is not anymore then.

Importance of the core voltage when overclocking

With the proliferation of computer games and related hardware came the so-called overclocking fashionable. If a CPU operated within the specified parameters, such as to bring about a higher clock frequency by an increase in performance, the current differences fall out even higher and the supply voltage may be interrupted for a short time so far, that stable operation is impossible. Raising the core voltage can counteract this, but usually leads to an increase in heat loss - these must then possibly be removed by additional measures.

  • Computer Architecture
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