Browse Definitions :
Definition

instruction set

Contributor(s): Matthew Haughn

An instruction set is a group of commands for a CPU in machine language. The term can refer to all possible instructions for a CPU or a subset of instructions to enhance its performance in certain situations.

All CPUs have instruction sets that enable commands to the processor directing the CPU to switch the relevant transistors. Some instructions are simple read, write and move commands that direct data to different hardware.

In CISC (Complex Instruction Set Computer) processors there is also a microcode layer, which involves programmable instructions stored in fast memory that may be updated. The RISC (Reduced Instruction Set Computer) architecture, on the other hand, has hard-wired control; it does not require microcode but has a greater base instruction set.

Enhancement instruction sets are more familiar to users as they have often been used in marketing a given CPU. Examples of this go back to the Pentium 166Mhz with MMX technologies marketed for enhancing Intel CPU multimedia performance.

MMX stands for MultiMedia eXtenstions, and refers to the extended instruction set. Other examples include MMX+, 3DNow!, 3DNow!+, SSE, SSE2, SSSE3, SSE4.1, SSE4A, AVX, AVX2 and XOP.

This was last updated in February 2014

Start the conversation

Send me notifications when other members comment.

Please create a username to comment.

-ADS BY GOOGLE

File Extensions and File Formats

Powered by:

SearchCompliance

SearchSecurity

  • computer worm

    A computer worm is a type of malicious software program whose primary function is to infect other computers while remaining ...

  • Single Sign-On (SSO)

    Single sign-on (SSO) is a session and user authentication service that permits a user to use one set of login credentials (e.g., ...

  • Certified Information Systems Auditor (CISA)

    Certified Information Systems Auditor (CISA) is a certification issued by ISACA to people in charge of ensuring that an ...

SearchHealthIT

SearchDisasterRecovery

  • business continuity plan (BCP)

    A business continuity plan (BCP) is a document that consists of the critical information an organization needs to continue ...

  • disaster recovery team

    A disaster recovery team is a group of individuals focused on planning, implementing, maintaining, auditing and testing an ...

  • cloud insurance

    Cloud insurance is any type of financial or data protection obtained by a cloud service provider. 

SearchStorage

Close