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TekSpek Guides
Green computing at home

Green computing at home

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This TekSpek explains what Green Computing is, what it means to the consumer, and how energy-efficient components can be beneficial in the home.

What is Green Computing?
Put simply, green computing is the practise of &using computing resources efficiently&.

With the rising costs of energy, and the constant battle against pollution, green computing has become more apparent in recent years and is today a subject of focus that applies to both global corporations and the single home user.

On a global scale, government programs such as Energy Star have in recent years aimed to reduce waste by strictly regulating the efficiency requirements of computer hardware. However, for this particular TekSpek we'll be focussing on green computing on a much smaller scale and taking a look at what it means to your home computer.

The home computer consists of a multitude of components that have gone under scrutiny in the need to be energy efficient. Today, the average consumer is astutely aware of the running costs of electrical equipment and manufacturers are hoping to meet our more-efficient needs with a series of energy saving products. So, let's start at the top.

Today's operating systems, such as Microsoft's Windows Vista or Apple's Mac OS X to name a few, take advantage of energy-saving protocols such as ACPI (Advanced Configuration and Power Interface).

ACPI, an open standard power-management system, allows a user's operating system to adjust power usage of its connected hardware. It may all sound foreign, but you'll recognise it when your PC turns off its display or enters a "sleep" mode after periods of inactivity.

Sleep mode, in which a computer's RAM remains powered whilst nearly all other components are powered down, is one of the most common energy-saving features on a computer. However, users should be aware that functionality such as "sleep" or "hibernate" is only available on ACPI-compliant computers.

Software, as you'd expect, is constantly evolving to become more energy efficient, but what about the underlying hardware?

A computers CPU, or processor as it's commonly known, is generally rated for efficiency by its Thermal Design Point (TDP). Although not one of the best-advertised CPU features, the TDP lets a user know just how efficient a processor is.

For example, an Intel Core 2 Quad Q9650 has a TDP of 95W. In comparison, the Intel Core 2 Duo E8400 has a TDP of 65W. Though the quad-core chip may be the more powerful in terms of performance, the dual-core chip requires less energy, creates less heat, and is consequently more energy efficient.

But is it just that simple? Not quite. Today, the majority of CPUs have the ability to control power usage by undervolting. Such functionality is available as &SpeedStep& on Intel CPUs and &Cool 'n' Quiet& on AMD CPUs.

A computer's graphics card, or GPU, is often the biggest offender in terms of energy usage. Today's ultra-high-end solutions, such as AMD's Radeon HD 4870 X2, offer blazing performance at a significant cost. The aforementioned graphics card is known to consume in excess of a mammoth 350W of power when under load.

But is there another option? Unfortunately, if it's ultra-high-end graphics performance you need, there's very little compromise in terms of energy efficiency.

However, manufacturers are starting to provide greener solutions. NVIDIA, one of the world's largest GPU manufacturers, offers a Hybrid SLI technology that allows a computer system to switch between two or more GPUs. Using Hybrid SLI, a low-power GPU can be used for everyday computing tasks, and a more powerful and power-hungry GPU can be called upon as and when required.

The motherboard is a central component in desktop or notebook computers, and today's manufacturers have no shortage of energy-saving features.

Perhaps the most common energy-saving feature is the use of higher-quality components. The use of ferrite chokes as opposed to iron chokes, for example, is one means to reduce energy loss.

In addition, motherboard manufacturers now compete with one another not only for performance, but also for efficiency. Today's boards are available with longer-life capacitors, dynamically-switching power phases, and an array of other energy-saving options.

Users should be aware, though, that whilst manufacturers compete to become the most energy-efficient, it's a tough task to sieve through the large amounts of marketing to see which boards really are the most efficient.

We're not done yet. Even a simple component such as a hard-disk drive could be wasting energy. Did you know that a 2.5in hard-disk drive is likely to consume less power than a 3.5in hard-disk drive of the same capacity? Well, you do now.

As of mid-2007, all Energy Star compliant Power Supply Units (PSUs) are required to be 80 per cent efficient. Look further, though, and that efficiency can rise.

80 PLUS, a PSU-rating scheme, currently offers four unique ratings; 80 PLUS, 80 PLUS Bronze, 80 PLUS Silver and 80 PLUS Gold. Effective since early 2008, the four ratings represent full-load efficiencies of 80 per cent, 82 per cent, 85 per cent and 87 per cent, respectively. The higher the rating, the more efficient the power supply.

What else can the home user do?
An occasionally overlooked talking point is what to do with a computer that's outlived its purpose? Historically, such systems are added to a scrap pile where they deposit harmful materials such as mercury and lead.

To avoid such occurrences, a major initiative of green computing is recycling. Instead of throwing computers away, they can now be recycled at local stores or donated to charity.

Taking all the above into account, just how efficient is your current computer? Unless you've been actively following the green-computing trend, the answer is probably &not very&.

With the possible savings in running costs, a computer consisting of more energy-efficient components is quickly becoming more appealing. Expect the green-computing trend to gather pace in the coming years, and keep the above information at hand - it could save you money on future electricity bills!