Actually, PowerPC refers to a type of microprocessor chip, not an entire computer. It is the result of an alliance between Apple, IBM, and Motorola. Processor chips for Apple Macintosh computers have been made by Motorola, and have had a different numbering scheme from the Intel-made chips in IBM-compatibles. Remember, IBM PCs started out with the 8088 and progressed to the 80286, 80386, 80486, and Pentium (commonly referred to as the 80x86 line). The Apple Macintosh, or Mac, started out with the 68000 and progressed to the 68020, 68030, and 68040 chips (commonly referred to as the 680x0 line).
All these chips have been based on a common operational scheme, or architecture, called Complex Instruction Set Computing, or CISC. These chips contain a wide variety of instructions that enable the computer to carry out its functions. However, Apple, IBM, and Motorola felt that CISC technology has almost reached it performance peak. They decided to jump off the CISC bandwagon and tap the power of an alternative chip architecture known as Reduced Instruction Set Computing, or RISC.
The main difference between CISC and RISC is that instead of the wide variety of instructions contained in a CISC chip, a RISC chip only contains the instructions used most often. However, it can execute these basic instructions very quickly. When complex instructions are required, the RISC chip builds them by combining sets of basic instructions. This means that most operations are handled far more rapidly by RISC than by CISC.
RISC chips of various types have been around a long time, powering various systems such as engineering workstations and high-end graphics machines. However, until the development of the PowerPC chip, nobody marketed an affordable RISC chip that could run familiar operating systems such as DOS, Windows, and the Mac OS. Apple’s line of PowerPC computers, called PowerMacs, are the first systems to reach the consumer market. IBM plans to release a line of personal computers powered by the PowerPC chip very soon. And just like the various degrees of speed and power of the Pentium and Pentium Pro, PowerPC chips come in various models ranging from entry-level to state-of-the-art.
Will RISC-based PowerPC chips eventually replace the CISC-based chips manufactured by Intel and others? No one knows for sure. Only time will tell. But for those wanting the fastest personal computers currently available, the PowerPC is the power plant of choice.
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