Central Processing Unit and Cooling Systems May 2016 | Page 11

Two major CPU architectures are related to instruction sets:


Reduced Instruction Set Computer (RISC) - Architectures use a relatively small set of instructions. RISC chips are designed to
execute these instructions very rapidly.



Complex Instruction Set Computer (CISC) - Architectures use a broad set of instructions, resulting in fewer steps per operation.

The CISC instructions are decoded before being executed in a modern processor. This preserves compatibility with older software.
Some Intel CPUs incorporate hyperthreading to enhance the performance of the CPU. With hyperthreading, multiple pieces of code
(threads) are executed simultaneously in the CPU. To an operating system, a single CPU with hyperthreading performs as though there
are two CPUs when multiple threads are being processed.