Dual-voltage CPU
Encyclopedia
A dual-voltage CPU uses a split-rail design to allow lower voltages to be used in the processor core while the external Input/Output
(I/O) voltages remain 3.3 volts for backwards compatibility.
A single-voltage CPU uses a single power voltage throughout the chip, supplying both I/O power and internal power.
As of 2002 Microprocessor#Market statistics, most CPUs are single-voltage CPUs.
All CPUs before the Pentium MMX are single-voltage CPUs.
Dual-voltage CPUs were introduced for performance gain when increasing clock speeds and finer semiconductor fabrication
processes resulted in excess heat generation and power supply concerns, especially regarding laptop computers. Using a voltage regulator
, the external I/O voltage levels would be transformed to lower voltages in order to reduce power usage, resulting in less heat being produced with the ability to operate at higher frequencies.
VRT is a feature on older Intel P5
Pentium processors that are typically intended for use in a mobile environment. It refers to splitting the core voltage supply from the I/O voltage. A VRT processor has a 3.3 V I/O and 2.9 V core voltage, to save power compared to a typical Pentium processor which had both I/O and core voltage at 3.3V. All Pentium MMX and later processors adopted this so-called split rail power supply.
Input/output
In computing, input/output, or I/O, refers to the communication between an information processing system , and the outside world, possibly a human, or another information processing system. Inputs are the signals or data received by the system, and outputs are the signals or data sent from it...
(I/O) voltages remain 3.3 volts for backwards compatibility.
A single-voltage CPU uses a single power voltage throughout the chip, supplying both I/O power and internal power.
As of 2002 Microprocessor#Market statistics, most CPUs are single-voltage CPUs.
All CPUs before the Pentium MMX are single-voltage CPUs.
Dual-voltage CPUs were introduced for performance gain when increasing clock speeds and finer semiconductor fabrication
Semiconductor fabrication
Semiconductor device fabrication is the process used to create the integrated circuits that are present in everyday electrical and electronic devices. It is a multiple-step sequence of photolithographic and chemical processing steps during which electronic circuits are gradually created on a wafer...
processes resulted in excess heat generation and power supply concerns, especially regarding laptop computers. Using a voltage regulator
Voltage regulator
A voltage regulator is an electrical regulator designed to automatically maintain a constant voltage level. A voltage regulator may be a simple "feed-forward" design or may include negative feedback control loops. It may use an electromechanical mechanism, or electronic components...
, the external I/O voltage levels would be transformed to lower voltages in order to reduce power usage, resulting in less heat being produced with the ability to operate at higher frequencies.
VRT is a feature on older Intel P5
P5 (microarchitecture)
The original Pentium microprocessor was introduced on March 22, 1993. Its microarchitecture, deemed P5, was Intel's fifth-generation and first superscalar x86 microarchitecture. As a direct extension of the 80486 architecture, it included dual integer pipelines, a faster FPU, wider data bus,...
Pentium processors that are typically intended for use in a mobile environment. It refers to splitting the core voltage supply from the I/O voltage. A VRT processor has a 3.3 V I/O and 2.9 V core voltage, to save power compared to a typical Pentium processor which had both I/O and core voltage at 3.3V. All Pentium MMX and later processors adopted this so-called split rail power supply.