Pentium Pro is a sixth-generation x86 architecture microprocessor (P6 core) from Intel. It was originally intended to replace the earlier Pentium series of microprocessors in a full range of applications, but was later reduced to an narrow role as a server and high-end desktop chip. The Pentium Pro was capable of both dual- and quad-processor configurations. The Pentium Pro achieves a performance approximately 50% higher than that of a Pentium of the same clock speed. In addition to its new way of processing instructions, the Pentium Pro incorporates several other technical features including superpipelining, an integrated level 2 cache, 32-bit optimization, a wider address bus, greater multiprocessing, out-of-order completion of instructions, a superior branch prediction unit and speculative execution.

Pentium II is an x86 architecture microprocessor introduced by Intel in the year 1997. It was based on a modified version of the P6 core improved 16-bit performance and the addition of the MMX SIMD instruction set. The Pentium II series of processors are available in speeds of 233, 266, 300, 330, 350, 400 and 450 MHz. Some of the product highlights include the use of Intel’s 0.25 μm manufacturing process for increased processor core frequencies and reduced power consumption, the use of MMX bus (DIB) architecture to increase bandwidth and performance over single-bus processors, a 32 kB nonblocking level 1 cache, a 512 kB unified, nonblocking level 2 cache and data integrity and reliability features.

Pentium III is an x86 architecture microprocessor from Intel, introduced in the year 1999. Initial versions were very similar to the earlier Pentium II. The most notable difference is the addition of SSE instructions and the introduction of a serial number which was embedded in the chip during the manufacturing process. Pentium III processors are available in speeds of 650, 667, 700, 733, 750, 800, 850 and 866 MHz and 1 GHz. The Pentium III processor integrates PC dynamic execution microarchitecture, DIB architecture, a multi-transaction system bus and Intel’s MMX media enhancement technology. In addition to these features, it offers Internet streaming and single-instruction multiple-data (SIMD) extension. It has 70 new instructions to enable advanced imaging, 3D, streaming audio and video and speech recognition. Pentium III processors were superseded by Pentium IV. Pentium IV is a seventh-generation x86 architecture microprocessor from Intel. It uses a new CPU design called the netburst architecture. The netburst microarchitecture featured a very deep instruction pipeline, with the intention of scaling to very high frequencies. It also introduced the SSE2 instruction set for faster SIMD integer and 64-bit floating-point computation. It operates at frequencies of over 1GHz.

Pentium M is an x86 architecture microprocessor from Intel, introduced in the year 2003. It forms part of the Intel Centrino platform. The processor was originally designed for use in laptop personal computers (thus the ‘M’ for mobile). Pentium D is a series of microprocessors from Intel introduced in the year 2005. Pentium D was the first multicore CPU along with the Pentium Extreme Edition. It is the final processor to carry the Pentium brand name. The Pentium Extreme Edition series of microprocessors was introduced by Intel in the year 2005. It is based on the dual-core Pentium D processor.

Celeron processors were introduced by Intel as a low-cost CPU alternative for the Pentium processors. They were basically Pentium II processors without any L2 cache at all. However, this reduced the performance of Celeron processors as compared with AMD and Cyrix chips. Hence, subsequent Celeron versions (300A and up) were provided with 128 kB of L2 cache. It was about one-fourth the size of the Pentium cache but operated at the full speed of the respective CPU, rather than at half-speed as in the Pentium processors. Later Celeron versions were based on the Pentium III, Pentium IV, and Pentium M processors. These processors are suitable for most applications, but their performance is somewhat limited when it comes to running intense applications. Xeon are high-end processors having a full-speed L2 cache of the same size as the Pentium cache. These processors are used for high-performance servers and workstations.

Embedded microprocessors are microprocessors designed for embedded applications and not for use in personal computers. They are mostly used for embedded data control applications such as data processing, data formatting, I/O control, DMA data transfer, etc. In other words, they are designed for specific applications rather than for general-purpose applications. Intel has developed a number of embedded microprocessors, namely Intel 80960, Intel 80376 and embedded versions of 80486, 80386 and 80186 microprocessors. Other embedded microprocessors include Motorola’s Coldfire, Sun’s Sparc, Hitachi’s SuperH, Advanced RISC Machines’ ARM, and MIPS Computer Systems Inc.’s MIPS processors.