Cool'n'Quiet
Encyclopedia
Cool'n'Quiet is a CPU
speed throttling and power saving technology introduced by AMD with its Athlon 64 processor line. It works by reducing the processor's clock rate
and voltage
when the processor is idle. The aim of this technology is to reduce overall power consumption and lower heat generation, allowing for slower (thus quieter
) cooling fan
operation. The objectives of cooler and quieter result in the name Cool'n'Quiet. The technology is similar to Intel's SpeedStep
and AMD's own PowerNow!
, which were developed with the aim of increasing laptop battery life by reducing power consumption.
Due to their different usage, Cool'n'Quiet refers to desktop and server chips, while PowerNow! is used for mobile chips; the technologies are similar but not identical. This technology was also introduced on "e-stepping" Opteron
s, however it is called Optimized Power Management, which is essentially a re-tooled Cool'n'Quiet scheme designed to work with registered memory
.
Cool'n'Quiet is fully supported in Linux from 2.6.18 (using the powernow-k8 driver) and FreeBSD from 6.0-CURRENT onward.
Unlike Windows XP, Windows Vista only supports Cool'n'Quiet on motherboards that support ACPI
2.0 or later. With earlier versions of Windows processor drivers Cool'n'Quiet software needs to be installed.
In addition to the CPU drivers offered by AMD, several motherboard manufacturers have released software to give the end user more control over the Cool 'n' Quiet feature, as well as the other new features of AMD processors and chipsets. There are also third party applications like Phenommsrtweaker that provide custom Cool'n'Quiet. Using these applications, one can even have control over the CPU voltage.
Central processing unit
The central processing unit is the portion of a computer system that carries out the instructions of a computer program, to perform the basic arithmetical, logical, and input/output operations of the system. The CPU plays a role somewhat analogous to the brain in the computer. The term has been in...
speed throttling and power saving technology introduced by AMD with its Athlon 64 processor line. It works by reducing the processor's clock rate
Clock rate
The clock rate typically refers to the frequency that a CPU is running at.For example, a crystal oscillator frequency reference typically is synonymous with a fixed sinusoidal waveform, a clock rate is that frequency reference translated by electronic circuitry into a corresponding square wave...
and voltage
Voltage
Voltage, otherwise known as electrical potential difference or electric tension is the difference in electric potential between two points — or the difference in electric potential energy per unit charge between two points...
when the processor is idle. The aim of this technology is to reduce overall power consumption and lower heat generation, allowing for slower (thus quieter
Quiet PC
A quiet PC is a personal computer that makes little noise. Common uses for quiet PCs include video editing, sound mixing, home servers, and home theater PCs. A typical quiet PC uses quiet cooling and storage devices and energy-efficient parts....
) cooling fan
Computer fan
A computer fan is any fan inside, or attached to, a computer case used for cooling purposes, and may refer to fans that draw cooler air into the case from the outside, expel warm air from inside, or move air across a heatsink to cool a particular component...
operation. The objectives of cooler and quieter result in the name Cool'n'Quiet. The technology is similar to Intel's SpeedStep
SpeedStep
SpeedStep is a trademark for a series of dynamic frequency scaling technologies built into some Intel microprocessors that allow the clock speed of the processor to be dynamically changed by software...
and AMD's own PowerNow!
PowerNow!
PowerNow! is speed throttling and power saving technology of AMD's processors used in laptops. The CPU's clock speed and VCore are automatically decreased when the computer is under low load or idle, to save battery power, reduce heat and noise...
, which were developed with the aim of increasing laptop battery life by reducing power consumption.
Due to their different usage, Cool'n'Quiet refers to desktop and server chips, while PowerNow! is used for mobile chips; the technologies are similar but not identical. This technology was also introduced on "e-stepping" Opteron
Opteron
Opteron is AMD's x86 server and workstation processor line, and was the first processor which supported the AMD64 instruction set architecture . It was released on April 22, 2003 with the SledgeHammer core and was intended to compete in the server and workstation markets, particularly in the same...
s, however it is called Optimized Power Management, which is essentially a re-tooled Cool'n'Quiet scheme designed to work with registered memory
Registered memory
Registered memory modules have a register between the DRAM modules and the system's memory controller. They place less electrical load on the memory controller and allow single systems to remain stable with more memory modules than they would have otherwise...
.
Cool'n'Quiet is fully supported in Linux from 2.6.18 (using the powernow-k8 driver) and FreeBSD from 6.0-CURRENT onward.
Unlike Windows XP, Windows Vista only supports Cool'n'Quiet on motherboards that support ACPI
Advanced Configuration and Power Interface
In computing, the Advanced Configuration and Power Interface specification provides an open standard for device configuration and power management by the operating system....
2.0 or later. With earlier versions of Windows processor drivers Cool'n'Quiet software needs to be installed.
In addition to the CPU drivers offered by AMD, several motherboard manufacturers have released software to give the end user more control over the Cool 'n' Quiet feature, as well as the other new features of AMD processors and chipsets. There are also third party applications like Phenommsrtweaker that provide custom Cool'n'Quiet. Using these applications, one can even have control over the CPU voltage.
Processors supporting Cool'n'Quiet
- Athlon 64Athlon 64The Athlon 64 is an eighth-generation, AMD64-architecture microprocessor produced by AMD, released on September 23, 2003. It is the third processor to bear the name Athlon, and the immediate successor to the Athlon XP...
and X2Athlon 64 X2The Athlon 64 X2 is the first dual-core desktop CPU designed by AMD. It was designed from scratch as native dual-core by using an already multi-CPU enabled Athlon 64, joining it with another functional core on one die, and connecting both via a shared dual-channel memory controller/north bridge and...
- all models - Athlon 64 FX - FX-53 (Socket 939Socket 939Socket 939 is a CPU socket released by AMD in June 2004 to supersede the previous Socket 754 for Athlon 64 processors. Socket 939 was succeeded by Socket AM2 in May 2006. It is the second socket designed for AMD's AMD64 range of processors.-Availability:...
only) and higher - Athlon IIAthlon IIAthlon II is a family of AMD multi-core 45 nm central processing units, which is aimed at the midrange to budget market and is a complementary product lineup to the Phenom II.-Features:...
- all models - SempronSempronSempron has been the marketing name used by AMD for several different budget desktop CPUs, using several different technologies and CPU socket formats. The Sempron replaced the AMD Duron processor and competes against Intel's Celeron series of processors...
- Socket 754Socket 754Socket 754 is a CPU socket originally developed by AMD to succeed its Athlon XP platform . Socket 754 was the first socket developed by AMD to support their new consumer version of the 64 bit microprocessor family known as AMD64.-Technical specifications:Socket 754 was the original socket for...
: 3000+ and higher; Socket AM2Socket AM2The Socket AM2, renamed from Socket M2 , is a CPU socket designed by AMD for desktop processors, including the performance, mainstream and value segments...
: 3200+ and higher - Opteron - E-stepping and higher, branded as Optimized Power Management
- PhenomPhenom (processor)Phenom is the 64-bit AMD desktop processor line based on the K10 microarchitecture, in what AMD calls family 10h processors, sometimes incorrectly called "K10h". Triple-core versions belong to the Phenom 8000 series and quad cores to the AMD Phenom X4 9000 series...
- all versions support Cool'n'Quiet 2.0 - Phenom IIPhenom IIPhenom II is a family of AMD's multi-core 45 nm processors using the AMD K10 microarchitecture, succeeding the original Phenom. Advanced Micro Devices released the Socket AM2+ version of Phenom II in December 2008, while Socket AM3 versions with DDR3 support, along with an initial batch of...
- supports Cool'n'Quiet 3.0 - AMD FusionAMD FusionAMD Fusion is the marketing name for a series of APUs by AMD. There are two flavors of Fusion currently available, one with its CPU logic based on the Bobcat core and the other its CPU logic based on the 10h core. In both cases the GPU logic is HD6xxx, which itself is based on the mobile variant of...
- see Phenom II