Pentium III

The Pentium III processor shares many of the Pentium II's characteristics. It supports dynamic execution (as the Pentium Pro also did) and MMX technology, has 32K of L1 cache, and has either 256K or 512K of L2 cache. The Pentium III runs at a speed of 450 MHz to 1000 MHz, or 1 GHz.

The Pentium III chip offers 70 additional instructions that are integrated into the chip, enhancing the user's experience with 3-D graphic applications. The Pentium III chip also supports a number of low-power states to help conserve energy when the system is not in use. This processor is designed to run on either 100 MHz or 133 MHz motherboards.

Also note that there is a Pentium III version of the Celeron chip that runs as fast as the Pentium III processor but again has the L2 cache memory reduced. So now there are multiple versions of the Celeron chip - the PII version and the PIII version.

The Pentium III processor shipped in the SEC2 package originally, but was then packaged as a PGA chip. The SEC2 goes in Slot 1, while the PGA chip is inserted into Socket 370.

Xeon

The Xeon processor is built on the Pentium II and Pentium III architecture - meaning that, like the Celeron, there is a PII version and PIII version of the Xeon. The Xeon chip is designed for higher-end systems, such as serverclass systems, and contains more cache memory than the typical PII and PIII. The Xeon comes in flavors of 512K, 1MB, and 2MB of L2 cache.

The Xeon can also address 64GB of RAM and is designed for multiprocessing systems. A multiprocessing system is a computer with a motherboard that supports multiple CPUs. The Xeon processor has been designed to coexist with two, four, or eight CPUs.

The Pentium II Xeon and Pentium III Xeon chips were originally packaged as an SEC that was placed in Slot 2, but later versions use the PGA and are placed in Socket 603. The Xeon chip also contains a thermal sensor that shuts the processor down if it starts to overheat. The Celeron is a scaled-down version of the Pentium II or III processor, and the Xeon is a step up from the Pentium II or III. There are also PIV (Pentium 4) versions of the processors:

• PIV XEON: Designed to work with a multiprocessing system that uses one or two processors.
• PIV XEON MP: Designed to work with a multiprocessing system that uses four or eight processors.