2
Introduction
Computer processor manufacturers are incorporating the ability to manage power use directly into their
newer processors. Processors recently released by both Intel and AMD include features that work with the
BIOS and operating system to lower power consumption. Along with being more environmentally friendly,
reduced power consumption results in reduced heat production. Less heat means lower fan speed require-
ments, thereby providing quieter, more efficient computers.
What is EIST?
Enhanced Intel SpeedStep Technology (EIST) is the term Intel uses for its processor power management
technology. This processor feature allows the system to dynamically adjust processor voltage and core fre-
quency as often as is required to decrease power consumption and decrease heat production. The pro-
cessor alters performance by changing bus-to-core frequency ratio and voltage. Only the internal core
frequency is altered - the front side bus (FSB) is not affected. To run at reduced power consumption, the
voltage is changed in step with the bus ratio.
What is Cool’n’Quiet
Cool’n’Quiet is the term AMD uses for its processor power management technology. This processor fea-
ture dynamically adjusts the operating frequency and voltage of a processor up to 30 times per second
depending on the CPU load. When full processor performance is not needed, the processor slows its fre-
quency, resulting in significant power savings, which results in cooler and quieter performance.
While Cool’n’Quiet technology is new to desktop processors, a similar technology from AMD has been
used in mobile processors for several years. This mobile processor technology is known as PowerNow!
Why are EIST and Cool’n’Quiet needed?
EIST and Cool’n’Quiet were created to lower power consumption when software activity does not require
the full capabilities of the processor. Reduced power consumption means reduced operating costs and
reduced heat production. Reduced heat production means reduced fan speed requirements. Reduced fan
speed requirements also mean reduced system noise.
This technology is also especially useful for portable computers, as reduced power consumption leads to
increased battery life.
What are the required components for EIST and Cool’n’Quiet to function?
For a system to take advantage of EIST or Cool’n’Quiet, the following system components must support the
feature:
•
Processor
•
Chipset
•
System BIOS
•
Operating system
•
Processor driver