|
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. ==External links== *(An Illustrated Guide to Pentiums (Karbos Guide) ) *(Processor Voltage >> PC Mechanic ) 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Dual-voltage CPU」の詳細全文を読む スポンサード リンク
|