Browse Definitions :
Definition

translation lookaside buffer (TLB)

Contributor(s): Matthew Haughn

A translation lookaside buffer (TLB) is a memory cache that stores recent translations of virtual memory to physical addresses for faster retrieval.

When a virtual memory address is referenced by a program, the search starts in the CPU. First, instruction caches are checked. If the required memory is not in these very fast caches, the system has to look up the memory’s physical address. At this point, TLB is checked for a quick reference to the location in physical memory.

When an address is searched in the TLB and not found, the physical memory must be searched with a memory page crawl operation. As virtual memory addresses are translated, values referenced are added to TLB. When a value can be retrieved from TLB, speed is enhanced because the memory address is stored in the TLB on processor. Most processors include TLBs to increase the speed of virtual memory operations through the inherent latency-reducing proximity as well as the high-running frequencies of current CPU’s.

TLBs also add the support required for multi-user computers to keep memory separate, by having a user and a supervisor mode as well as using permissions on read and write bits to enable sharing.

TLBs can suffer performance issues from multitasking and code errors. This performance degradation is called a cache thrash. Cache thrash is caused by an ongoing computer activity that fails to progress due to excessive use of resources or conflicts in the caching system.

This was last updated in September 2014

Continue Reading About translation lookaside buffer (TLB)

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

  • Whistleblower Protection Act

    The Whistleblower Protection Act of 1989 is a law that protects federal government employees in the United States from ...

  • smart contract

    A smart contract, also known as a cryptocontract, is a computer program that directly controls the transfer of digital currencies...

  • risk map (risk heat map)

    A risk map, also known as a risk heat map, is a data visualization tool for communicating specific risks an organization faces. A...

SearchSecurity

  • buffer underflow

    Buffer underflow, also known as buffer underrun or buffer underwrite, is a threat to data that typically occurs when the ...

  • digital signature

    A digital signature is a mathematical technique used to validate the authenticity and integrity of a message, software or digital...

  • denial-of-service attack

    A denial-of-service attack is a security event that occurs when an attacker prevents legitimate users from accessing specific ...

SearchHealthIT

SearchDisasterRecovery

  • virtual disaster recovery

    Virtual disaster recovery is a type of DR that typically involves replication and allows a user to fail over to virtualized ...

  • tabletop exercise (TTX)

    A tabletop exercise (TTX) is a disaster preparedness activity that takes participants through the process of dealing with a ...

  • risk mitigation

    Risk mitigation is a strategy to prepare for and lessen the effects of threats faced by a data center.

SearchStorage

  • secondary storage

    Secondary storage is storage for noncritical data that does not need to be frequently accessed.

  • Pure Storage

    Pure Storage is a provider of enterprise data flash storage solutions designed to substitute for electromechanical disk arrays.

  • yobibyte (YiB)

    A yobibyte (YiB) is a unit of measure used to describe data capacity as part of the binary system of measuring computing and ...

Close