The largest challenge for the mobile system designer in developing systems based on new processor architectures is managing thermal energy efficiently. As mobile systems do not usually contain a cooling fan for internal components, heat is dissipated by using innovative thermodynamic design techniques such as heat pipes, thermal sensors, and by using the mobile system chassis to vent heat externally. Proper thermal design is critical in ensuring that mobile systems are reliable. Components that run too hot will be more likely to fail during normal usage and may reduce the life of the system.

The first notebook systems based on the 75-MHz Pentium(R) processor were developed with a target thermal operating range of 6.5 watts maximum and 3 watts typical while operating at 3.3 volts. These energy values are based on experiments that Intel developed to determine the maximum amount of power consumed by real-world applications and benchmarks. The 6.5 watt threshold required significant thermal engineering design by system manufacturers. Higher performance processors operating at 3.3 volts represent an even greater challenge to the mobile designer.

To help solve thermal issues, Intel developed Voltage Reduction Technology, which is integrated into new versions of the 75, 90, and 120-MHz Pentium processors. The external pins of the Pentium processor with Voltage Reduction Technology remain powered at 3.3 volts, which allows the processor to communicate with existing 3.3 volt components in the system. The internal core of the processor operates at 2.9 volts, resulting in up to a 40 percent power savings over its desktop counterpart. Consequently, the Pentium processor 120 MHz boosts performance by 60 percent over the Pentium processor
75 MHz and by 30 percent over the Pentium processor 90 MHz without compromising battery life. Voltage Reduction Technology helps mobile vendors more easily design and develop higher performance notebooks.

Pentium® Processor Mobile Power Specifications

Frequency                Voltage       Maximum Power*    Typical Power75 MHz                                     3.3  Volts              8.0 / 6.5 Watts             3.0 - 4.0 Watts75 MHz                                     2.9  Volts              6.0 / 4.5 Watts             2.0 - 3.0 Watts90 MHz                                     2.9  Volts              7.3 / 5.5 Watts             2.5 - 3.5 Watts120 MHz                                   2.9  Volts              7.1 / 5.5 Watts             2.5 - 3.5 Watts
* theoretical maximum power / measured maximum power