Search results
Results from the WOW.Com Content Network
When the logic gates toggle, energy is flowing as the capacitors inside them are charged and discharged. The dynamic power consumed by a CPU is approximately proportional to the CPU frequency, and to the square of the CPU voltage: [5] = where C is the switched load capacitance, f is frequency, V is voltage. [6]
ACPI 1.0 (1996) defines a way for a CPU to go to idle "C states", but defines no frequency-scaling system. ACPI 2.0 (2000) introduces a system of P states (power-performance states) that a processor can use to communicate its possible frequency–power settings to the OS. The operating system then sets the speed as needed by switching between ...
When it comes to high computer performance, one or more of the following factors might be involved: Short response time for a given piece of work. High throughput (rate of processing work tasks). Low utilization of computing resources. Fast (or highly compact) data compression and decompression. High availability of the computing system or ...
CPU time (or process time) is the amount of time that a central processing unit (CPU) was used for processing instructions of a computer program or operating system. CPU time is measured in clock ticks or seconds. Sometimes it is useful to convert CPU time into a percentage of the CPU capacity, giving the CPU usage.
The clock rate of a CPU is normally determined by the frequency of an oscillator crystal. Typically a crystal oscillator produces a fixed sine wave —the frequency reference signal. Electronic circuitry translates that into a square wave at the same frequency for digital electronics applications (or, when using a CPU multiplier , some fixed ...
An IBM RISC based architecture was used for the PowerPC CPU which was released in 1992. In 1994, Apple Computer introduced Macintosh computers using these PowerPC CPUs. Initially, this architecture met hopes for performance, and different ranges of PowerPC CPUs were developed, often delivering different performances at the same clock rate.
Low voltage modes are used in conjunction with lowered clock frequencies to minimize power consumption associated with components such as CPUs and DSPs; only when significant computational power is needed will the voltage and frequency be raised. Some peripherals also support low voltage operational modes.
The same is true for newer processors: When a single-core Intel CPU was 20% underclocked, the PC's performance was down only 13% with a 49% power reduction. [3] In general, the power consumed by a CPU with a capacitance C, running at frequency f and voltage V is approximately [4] =.