In May, Intel will release a low voltage Mobile Pentium III 600MHz, targeted at the back to school market for fall. The move to .18 micron for the Celeron will lower their power usage as well. SpeedStep will be included in all600MHz or faster Mobile Pentium IIIs.

Intel's SpeedStep technology enables, or more accurately 'disables', Mobile Pentium IIIs to run at 500MHz when unplugged from an AC power source. Running at a lower clock reduces the Pentium III's power needs and significantly increases battery life.

Most mobile users would gladly trade a few percentage points of performance for more battery life as long as they can have access to all the performance when plugged into the wall. SpeedStep is not a negative, however, its long-term competitiveness is questionable.

Transmeta's Crusoe CPU has a much more flexible and powerful system of power management named LongRun. Whether plugged into a wall socket or not, it dynamically changes its clock speed, and thereby its power consumption, to whatever level is necessary for the current task at hand. As we explained in our in-depth preview of the Crusoe, if a DVD needs about 50% of a Crusoe's top performance to run, the CPU will lower its MHz level to roughly that 50% level, thereby lowering its power consumption more than 50%. In comparison, a Mobile Pentium III with SpeedStep will still be running at 500MHz, using significantly more power than is required for the task.

As for AMD's Mustang-Mobile scheduled for sometime late this year, AMD has mentioned that it will come with something like Transmeta's LongRun technology. However, we have no details to give you right now.

So Intel has the only low-power x86 mobile solution that is available on the market right now. But competition is coming, so Intel will have to continue the quest for lower power if they want to stay ahead of the competition.