Graphics drivers (for X11 under whatever Free Software operating system you care to use) are one area where Free Software has plenty of room for improvement. My laptop has an nVidia GeForce 9600M in it, which means that there are two drivers I can use for it: the Free Software nv driver, or the proprietary nvidia one.

After switching video drivers, though, I thought the laptop felt a lot cooler in normal use. So, measurements. I used a watt-meter that sits between the wall socket and the power brick of the laptop to measure the following:

System idle, display on, nvidia driver: 40W
System idle, display blanked, nvidia driver: 33W
System idle, display on, nv driver: 42W
System idle, display blanked, nv driver: 35W

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