The Crusoe uses only 1-2 watts when running intensive calculations such as software DVD playback. When less processing power is needed, such as when writing e-mail, the Crusoe can fractionally cut its voltage and clock speed quickly and on the fly, even all the way down to 10-20 milliwatts. This LongRun system saves battery power and will let a Crusoe device run longer than other devices without a recharge.
So if you're playing a game of Pong on your Crusoe device, and Pong only needs 40% of the processing power that your Crusoe CPU can provide, then it will sense this and run at about 40% speed, thereby saving you plenty of battery life yet giving you smooth Pong action.
To makes things even better, Transmeta says that power needs decrease cubicaly as clock speeds drop, so the power savings of running at 40% clock speed are greater than 60%.
In comparison, Intel's .18 micron Mobile Pentium III at 400MHz uses approximately 7.5 watts. When less processing power is needed and you are trying to save battery life, the CPU can cycle on and off to save battery life but cannot scale itself to the task at hand.
So if you're playing a game of Pong on your Pentium III device, and Pong only needs 40% of the processing power that your Pentium III CPU can provide, one of two things can happen. If you are trying to save power, the CPU can effectively cycle on and off. Sometimes this works fine, but often in real-time tasks it will drop frames and get jerkiness when a task needs to use the CPU and the CPU is off at the moment.
The alternative is to run at full power and watch a perfectly smooth Pong ball fly as your battery quickly drains to nothing. Another possibility is Intel's SpeedStep technology, which runs the CPU at a lower speed when running off the battery, but this speed is not constantly adjustable like with LongRun on the Crusoe.