PC Hardware

Xenon, the Premium Pentium

Intel has labeled a new CPU brand to denote high-end server and high-performance desktop use. First introduced in June, 1998, the Xenon line commands a premium price and offers extra performance-enhancing technology. The Pentium II models incorporate 7.5 million transistors, clock speeds to 450 MHz, bus speeds of 100 MHz, full-speed L2 caches in varying sizes up to 2 MB, new multiprocessing capabilities, and compatibility with previous Intel microprocessor generations. All models use the SEC package.

Pentium III Processor

The Intel Pentium III processor is the newest member of the P6 family. With 28 million transistors, speeds from 500 to 733 MHz, and system bus speeds of 100 to 133 MHz, they mark a significant jump in PC CPU technology. They employ the same dynamic execution microarchitecture as the PII-a combination of multiple branch prediction, data-flow analysis, and speculative execution. This provides improved performance over older Pentium designs, while maintaining binary compatibility with all previous Intel processors. The Pentium III processor, shown in Figure 4.13, also incorporates MMX technology, plus streaming SIMD extensions for enhanced floating-point and 3-D application performance. It also utilizes multiple low-power states, such as AutoHALT, Stop-Grant, Sleep, and Deep Sleep to conserve power during idle times.

Figure 4.13 The Intel Pentium III Processor

Intel offers a Xenon version of the Pentium III processor at 550 MHz, aimed at high-performance workstations and servers.


Motorola has been the mainstay CPU for Apple computers. The 68000 processor was introduced in 1979 as a 32-bit chip with a 16-bit data path. At that time, the 68000 outperformed the Intel 8086. In 1982, the 68010 arrived, adding virtual memory support and a cache capable of holding three instructions.

1984 saw the advent of the Macintosh II-series computer, which used the 68020 processor. It was the first full 32-bit chip, with a 32-bit data path, math coprocessor, and the ability to access up to 4 GB of RAM. Introduced in the same year as Intel's 80286 processor, the Motorola ran faster. However, it lacked the market share and third-party support to gain real marketplace momentum. PC clones offered more programs and at lower cost than the Apple offerings.

The 68030 chip, introduced in 1987, provided increased data and instruction speed. This was comparable to the 80386 chip. The 68040 processor was introduced (in the Macintosh Quadra) as a competitor to the 80486. It has internal caches for data and program code.

The Power PC processor was developed jointly by IBM, Motorola, and Apple. The name stands for performance optimization with enhanced RISC. The chips in this family of processors are suitable for machines ranging from laptop computers to high-powered network servers. It can run MS-DOS software without using emulation.