by Alexa Hartono

Created on: July 03, 2007   Last Updated: December 30, 2010

The world is in search of energy efficient computing. Free translation of low powered computing, which in turn refers to environmental-friendly computing. So far, computing is still one of the biggest energy consumer in our modern life.

There is one thing that closely related to it. Power Management. Power management for computer systems are desired for many reasons, particularly:

- For portable and embedded systems: to prolong battery life and reduce heat dissipation.
- For desktop systems: reduce cooling requirement and reduce noise.
- For supercomputers: reduce operating costs from energy and cooling.

Lower power consumption also means low heat dissipation, which increases system stability, and less energy use, which saves money and reduces the ecological footprint of computing towards the environment.

So far, the world is still in search of an environmental-friendly microprocessor that can perform at outstanding speed. At present, the two biggest microprocessor producer Intel and AMD have given you their 'heavenly promises' of green computing. There is a technique called Dynamic Voltage and Frequency Scaling or DVFS. It is an energy-saving technique that consists of varying the frequency and voltage of a microprocessor in realtime according to processing needs.

Intel SpeedStep, AMD Cool'n'Quiet, AMD PowerNow!, VIA PowerSaver: allows the clock speed of a processor to be dynamically changed depending on workload levels. Newer Intel Core processors support ultra-fine power control over the function units within the processors.

At the level of operating system power management takes the form called hibernation. When computer system hibernates it dumps the entire contents of the RAM to disk and powers down the entire machine. On startup it reloads the data.

Hibernation allows the system to be completely powered off while in hibernate mode. This requires a file the size of the installed RAM to be placed on the hard disk, using up space even when not in hibernate mode. Hibernate mode is enabled by default in some versions of Windows and can be disabled in order to recover this disk space.

Disk Space...a little difficult to work without it. Regarding our modern life computer dependency...Actually, a computer can be compared to a car. The 'heavier' the load, the slower it goes and the more energy it uses. Even if you used the latest version, but if you make it work overload with certain operating system, your computer will go slow and eat more energy than it's supposed to be. Well, it might still use the same watts for the microprocessor, but more on fan and as you feel hot working with it, you'll need extra fan of air-conditioner for yourself.

Do you remember when you felt really satisfied with your computer speed? Aside from film, war and pop culture there is another thread of capitalism. Interdependency of hardware and operating system. Operating system is getting heavier, so each time you'll always feel you need to spend more on hardware....The devil's cycle?

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