LongRun and LongRun2 are
power management
Power management is a feature of some electrical appliances, especially copiers, computers, computer CPUs, computer GPUs and computer peripherals such as monitors and printers, that turns off the power or switches the system to a low-power st ...
technologies introduced by
Transmeta. LongRun was introduced with the
Crusoe Crusoe may refer to:
Art, entertainment, and media
* ''Crusoe'' (film), a 1989 film by Caleb Deschanel based on the novel ''Robinson Crusoe''
* ''Crusoe'' (TV series), a 2008 television series based on the novel ''Robinson Crusoe''
* Crusoe the ...
processor, while LongRun2 was introduced with the
Efficeon
The Efficeon processor is Transmeta's second-generation 256-bit VLIW design released in 2004 which employs a software engine Code Morphing Software (CMS) to convert code written for x86 processors to the native instruction set of the chip. Like i ...
processor. LongRun2 has since been licensed to
Fujitsu,
NEC,
Sony
, commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professiona ...
,
Toshiba
, commonly known as Toshiba and stylized as TOSHIBA, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. Its diversified products and services include power, industrial and social infrastructure systems, ...
, and
NVIDIA
Nvidia CorporationOfficially written as NVIDIA and stylized in its logo as VIDIA with the lowercase "n" the same height as the uppercase "VIDIA"; formerly stylized as VIDIA with a large italicized lowercase "n" on products from the mid 1990s to ...
.
LongRun automatically adjusted the processor, moving between higher performance but higher power, and lower power but lower performance. The goals of the automation could be adjusted. One control offered processor frequency levels, and the ability to set a minimum and maximum "window", where the automatic controls would not adjust the speed outside of the window. A second control offered a target of either "economy" or "performance". Some versions offered a third control that adjusted the processor based on power rather than speed.
LongRun was based primarily on reducing the clock frequency and voltage supplied to the processor, now commonly called
DVFS. Lower frequency reduces performance but also allows voltage reduction, and can yield both power savings and improved efficiency. LongRun2 built further on this by incorporating process technology aimed at reducing variations in the manufacturing process and thereby improving yields.
References
External links
Official description of LongRun2 recovered from the Internet Archive as of 2009.
Embedded microprocessors
Computer hardware tuning
Clock signal
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