I am ashamed to admit that whenever I, or the company I work for, bought a computer in the past, I never considered questioning its power consumption. I, like most people, just took it for granted that the machine had been built to suit your average users needs, and that it was as energy efficient as possible;  beside, computer power consumption was so low, that it wasn't something to be really concerned about, or so we were lead to believe.

It is clear now, that it was this complacent attitude that has got us into the current energy crisis, and I bear my share of responsibility. Even if you don't feel, as an individual consumer, thats its your problem, legislative changes, and higher than inflation, energy tariff increases, are going to make it an issue in your life, whether you like it or not. If you own or manage a corporate computer energy consumption is bound to become a issue that will require managements time and attention.

Power Consumption of PC Components

Although I can't do anything about the past, I can do something about the next computer that I, or Jumping Bean, the company I work for, buy.  Unfortunately the power that your standard desktop PC needs to run depends a lot on what  type of hardware you are usinging.  The table below gives some rough idea of the different amount of power each component of your PC needs to run.

It is clear from the above table that PC power consumption can be quiet complex to calculate and depends largely on what components you have.  One general observation though, is to only buy the processing power that you need. This may seem obvious, but we often buy PCs with powerful peripherals and processors that will never be used to full capacity.

In some respects, just like there is software bloat, so too there is hardware bloat. With software bloat, each year, your spreadsheet and word processing application get more and more features, requiring more and more powerful hardware to run, but do you use any of these new features? The truth is that most people only use the capabilities of their office productivity suites that were available over 8 eyar ago.

This trend is observable with hardware too. This is particularly true with:

• video cards,
• disk capacity and  access speeds,
• and of course processor speeds.

Most users' machines spend their time idle, waiting for the user to take some action requiring hardware intervention. Much of the time the processors is only using 10% of its capacity. The fact is, that processors, for everyday tasks, surpassed the speed of human thought and reaction times, years ago.

This is particularly true when it comes to video cards. I cannot tell you how many businesses I have seen where the desktop computer is running a powerful video card, when all the user need is a standard VGA compatible card to run their spreadsheet application or browse the web.

So don't believe the marketing hype and think you need to get the latest, fastest processor to do your job, or that your video card needs more memory to display your spreadsheet  in crisper colours. The evidence that you current desktop machines have far more power than you need, is in the explosive growth of  low powered PC and the rise of the low powered ARM processor. Within the next few years, these light weight, low energy usage machines are set to surpass desktop and laptop sales, especially as devices become more specialised.

Power Consumption of External PC Peripherals

Beside the PC itself, one should also consider the power consumption of your external peripherals such as your printer, monitor, speakers and ADSL modems. LCD monitors are extremely economical when it comes to power consumption. Their consumption is in the region of 25 -50 watts compared to CRT which consume like 60-80 watts for a 15 inch model to almost 70 to 150 for 17 and 19 inch models. Currently CRT monitors are cheaper than LCD monitors but the price differential is falling and LCDs have other advantages, like taking less desk-space and lasting longer than CRT monitors.

When it comes to other peripherals such as printers there is no much information available, although we will be carrying out some tests on our own equipment. Stay tuned and we will let you know the results.

Conclusion- Check Before you Buy

There is not much information available out there on what the best options are for many peripherals. Make sure that you check the power rating of any peripherals before you buy and calculate the power consumption of your PC overall before buying. The energy savings that you will make will more than pay back the time involved, not to mention your contribution to saving the planet.