Obsolete before old: What’s the lifespan of your laptop?

It's difficult to specify the lifespan of laptops, as they are so often junked before they are broken. This is in part due to planned obsolescence — a devious ploy by manufacturers bolstered by marketing strategies to make us fall out of love with a product hastily.

Planned obsolescence's running mate is Moore's law, which decrees that every two years the computing world doubles the amount of transistors on a computer chip and therefore the power of the computer. So you might say the average lifespan of a laptop is two years. Gulp. One metric tonne of electronic scrap from personal computers contains more gold than that recovered from 17 tonnes of gold ore.

Where will it all end? Moore's law should see transistors miniaturising every two years until we reach technological singularity — the point at which computers gain human-level intelligence and can build better versions of themselves. Others think time will soon be up on Moore's law, as computers will run out of matter and energy — by 2007, computers were reckoned to be drawing 4-5% of the world's power. Heat is the enemy of Moore's law. Those transistors packed on chips must be kept cool, so must the vast data storage centres, whose energy consumption, in 2010, was growing by 12% a year.

We need to keep our cool, too. There's a huge amount of skill and knowledge online about how to make old computers worth their weight in gold. People who have dealt with IT for not-for-profits where there has never been much money for shiny new IT are particularly expert. Try Itforcharities.co.uk for a list of organisations waiting to take on your "obsolete" model and Jayne Cravens' postings on "old tech" at coyotecommunications.com.

An untold truth is that we use a tiny fraction of each computer's capacity: you could say we're already outwitted by them. Unless we wise up, we'll soon be overtaken by the machines.

Lucy Siegle, New York Times