If you could take 7 million cars off the road, do you think it would have a positive impact on the environment and energy use? If that doesn't sound like much, how about planting 900 million trees? Or tearing down 65 coal-fired power plants? That's what MiserWare claims Granola, its free power management tool, would save the equivalent of if every PC in the world used it to reduce their current energy use by just 10 percent. Granola uses dynamic voltage and frequency scaling (DVFS) to throttle back your computer's power use when its load is low. Think of it as an automatic dimmer switch for your CPU. It works on both laptop and desktop PCs. And Granola goes further than the built-in power management options in recent versions of Windows.
Granola's main page listed our annual savings in kilowatt-hours, money, carbon dioxide, and CPU energy, as well as total carbon dioxide offset by the Granola community as a whole--the equivalent of nearly a quarter-million trees. Most of the time, Granola is minimized to the system tray. Clicking Settings opened a panel that let us set our power savings level, enable scheduling, configure settings such as currency and reporting, and enter our energy costs per kilowatt-hour (it's on your electric power bill). The scheduling option disables the policy selection slider, so we unchecked it. This let us change the program's action on our system's power settings from Lowest Speed, which produced the greatest savings, to Highest Power, which turns off power management. We could also toggle between low, medium, and high settings from the task bar icon as well as submit feedback to the developers.
Your computer uses more power than you might realize; that's where all that heat comes from. A secondary (but not-to-be-underestimated) benefit of Granola is reduced heat output, which keeps your PC performing crisply and helps its inner workings last longer. Granola's developers may be right: if everyone used it, the world would be a cleaner and greener place.