Intel Mobile Pentium microprocessor family

Mobile Pentium microprocessors had the same features as desktop Pentiums with the following exceptions:

• Core voltage on mobile Pentiums was lower than on desktop Pentium microprocessors, usually 2.9 Volt or 3.1 Volt. This directly translated into lower power consumption.
• Mobile CPUs didn't support dual-processing and processor upgrade features.
• Local Advanced Programmable Interrupt Controller was eliminated from the mobile Pentium CPUs.

Mobile processors were manufactured in two packages:

• Ceramic PGA package. These processors had the same part numbers as desktop Pentium processors, but could be easily identified as mobile processors from other markings on the chip. Specifically, some processors had core voltage (2.9V or 3.1V) marked on the top of the chip, while other processors had "IMPP" engraved on the back of the CPU. It is also possible to use S-Spec number (usually printed right after the part number) to identify mobile processors.
• Tape Carrier Package. Microprocessors in this package had much smaller size and very low profile, but this package could not be used by end-users because it required additional processing (lead forming and reflowing onto the PCB).