Kate's Comment

The music and movies industry are keen to tell us how enormously energy intensive downloading media can be. But just how much energy does get used when you download stuff from the Internet? I plugged some numbers from our data centre into my calculator to find out! The answer? About 5.9 Watt-hours per Megabyte, but as little as 1.8 Wh/MB for some configurations.

Over the last two years there has been a lot of debate about what the embedded energy of a PC or server is compared with how much power it uses. I have crunched the numbers and believe that the figure for a server is about 1,000,000 Watt-hours (1MWh). Here is how I worked it out, and why it means that you should sweat the desktops but replace the servers.