Speed and Memory

Earth use less than 5% of your processor (about 1% on our test computer) when it is not being actively used. So a spinning Earth in a web browser or on your desktop uses very little processor time. It was designed this way so that it could run in the background without slowing down your computer and annoying users. Also it does not use your hard disk, so it can't slow your computer down that way either.

Earth uses your 3D graphics card to do most of its work. This is why it appears to be doing a lot but doesn't slow down your computer. It will, of course, use more processing power when you are zooming and scrolling around the Earth, but at that time you probably aren't doing anything else anyway, so that shouldn't be a problem.

Earth was designed to run inside a web browser, which limits the amount of memory it can use. This has meant that Earth is careful not to use too much memory. But providing satellite day/night photos and cloud photos on a 3D Earth does use a lot of memory. Terrain shading uses up even more. But considering all that, and the animation of the last 24 hours of global cloud, Earth aims to use less 32 Meg of RAM. Compare this with Google Earth, which easily uses over 300 Meg of RAM on our test computer; 10 times the amount. Note: an upcoming release of Earth will allow you to significantly reduce memory usage by turning off various features like terrain shading or cloud animation.

There are currently 3 versions of Earth, the web page applet, a low memory desktop gadget and a high memory, high quality desktop application (which uses up to 256 Meg RAM). The low memory desktop gadget is designed to stay running on your desktop while minimizing the use of memory and processor. The high quality Earth application aims to provide a quality view of the Earth when viewing the whole Earth full-screen on your monitor. The Earth, sun shading and clouds look quite spectacular. You can quite happily leave the high quality version running on your desktop if you like, but computers without much spare RAM may find this a problem; which is why the low memory desktop gadget is useful. Any of the Earth programs can launch the high quality Earth application by going to the Earth menu bar and selecting Detail->Open Detailed Window.