instruction sets

Instruction Sets

The type of work a processor carries out is defined by its instructions, these instructions are coded in binary. All modern processors have their own instructions built-in for common tasks.

Having these instruction sets built-in allow the processor to carry out certain operations much faster. The instruction sets that are built-in depend on the processor's architecture, there are two main types of processor architecture on the market, CISC and RISC.

CISC (Complex Instruction Set Computer)
CISC processors have more internal instructions than its RISC counterpart allowing a more diverse set of operations. Although this may sound the best option, CISC processors are generally slower due to the complexity of the instructions. Some people think the benefit of having more complex instructions built-in outweigh the performance lose, but it would depend on the applications that the processor is going to run.

RISC (Reduced Instruction Set Computer)
RISC processors, as the name suggests, have fewer built-in instructions, this can add to the overall speed of the processor due to the simplicity of the instructions, but again the performance would depend on the type of applications the processor was to be used for.

Most modern processors have built-in instructions specifically designed for certain applications such as 3D graphics, audio manipulation, etc. One example of this would be the MMX (MultiMedia eXtension) technology which Intel built-in to its Pentium architecture in the late nineties. This was a special set of internal instructions that allowed the faster processing of audio and visual algorithms.