Friday, April 24, 2009

Spring cleaning

Now (even if you're reading this in November) is always a good time to do your computer housekeeping.

The two biggest enemies of electronics are bad power and heat. I covered the concerns of power surges in Storm Season. Where does heat come from and what can you do about it?

Everything you put into the computer generates heat. Every chip, spinning drive, and the power supply all add heat to the environment. And our quest for more and faster just means more heat. A faster CPU, fancier graphics adapter, bigger hard drive, more powerful sound card, even more memory each add their own increment to the heat load.

You can assume that every watt of power you put into the computer eventually ends up as heat after it is finished pushing the bits around. That means if you have a 200 watt power supply, it's the equivalent of sticking a large (incandescent) light bulb inside a metal box. In my childhood, that is how a toy stove could actually bake cookies.

Sometimes that metal box also exacerbates the issue. Open a full-size tower and you'll probably see at least 3 or 4 fans blowing on the various components. But most consumers and many businesses would rather have a compact size and quiet computer. Both of those criteria mean fewer fans and less space for air to circulate around the components. In a laptop, those issues are even compounded, although the components are somewhat more efficient with their use of electricity.

Speaking of quiet, most computers have thermostatic fans. When things inside start getting hot, the fan runs faster. If, all of a sudden, your computer starts making more noise and then quiets again; it was probably your fan putting on a burst of speed. If it always runs at high speed there may be something causing your computer to overheat. By the way, your CPU and hard drive also have thermometers in them and will shut themselves down before they dangerously overheat. There are numerous monitors of your internal temperatures available from any search engine. One that looked promising is available at (I have not tried it and don't vouch for it's legitimacy - always get your downloads from reputable sources and check them for malware)

Oh, that's right. The title up there is "Spring cleaning." The first thing to do to keep your computer cool is to get rid of the dust inside. Open the case and blow it out. Don't use a standard vacuum cleaner as they generate static electricity. You can buy high-quality "canned air." If you have access to a compressor, you can use that, too, at a moderate pressure. (I manage 150 devices in an industrial plant and blow them out with the building air. I have never had problems related to water or oil that may contaminate this unfiltered air.)

Be sure you have disconnected all the cables (especially the power) before you open the case. Then blow it out and the dust will go flying. I blow in both directions through all the vents and fans and even into the disc drive openings. Lift the shroud over the CPU and blow out all the heat sinks that look like vertical grids of metal.

When you reconnect the computer, check around that it has good airflow in and out of the vents. Keeping it in a closed cabinet will kill it quickly. Some serious power hobbyists have floor fans blowing at their computers to circulate even more air. Making the computer work harder also makes it use more power, so you might consider this tactic if you are into high-end gaming or video rendering that make heavy demands on the graphics system.

And don't feel guilty at all the dust you found. Even in very clean houses I find the computers full of dust. Just be sure there are no snakes or mice wrapped around the chips. (Just kidding, but you can find some scary stories on YouTube.)