Browse Definitions:
Definition

virtual CPU (vCPU)

Contributor(s): Matthew Haughn

A virtual CPU (vCPU) also known as a virtual processor, is a physical central processing unit (CPU) that is assigned to a virtual machine (VM).

By default, virtual machines are allocated one vCPU each. If the physical host has multiple CPU cores at its disposal, however, then a CPU scheduler assigns execution contexts and the vCPU essentially becomes a series of time slots on logical processors.

Because processing time is billable, it is important for an administrator to understand how his cloud provider documents vCPU usage in an invoice. It is also important for the administrator to realize that adding more vCPUs will not automatically improve performance. This is because as the number of vCPUs goes up, it becomes more difficult for the scheduler to coordinate time slots on the physical CPUs, and the wait time can degrade performance.

In VMware, vCPUs are part of the symmetric multi-processing (SMP) multi-threaded compute model. SMP also allows threads to be split across multiple physical or logical cores to improve performance of more parallel virtualized tasks. vCPUs permit multitasking to be performed sequentially in a multi-core environment.

 

This was last updated in April 2014

Continue Reading About virtual CPU (vCPU)

Start the conversation

Send me notifications when other members comment.

By submitting you agree to receive email from TechTarget and its partners. If you reside outside of the United States, you consent to having your personal data transferred to and processed in the United States. Privacy

Please create a username to comment.

-ADS BY GOOGLE

File Extensions and File Formats

Powered by:

SearchCompliance

SearchSecurity

  • password

    A password is an unspaced sequence of characters used to determine that a computer user requesting access to a computer system is...

  • adware

    Adware is any software application in which advertising banners are displayed while a program is running.

  • botnet

    A botnet is a collection of internet-connected devices, which may include PCs, servers, mobile devices and internet of things ...

SearchHealthIT

SearchDisasterRecovery

  • call tree

    A call tree -- sometimes referred to as a phone tree -- is a telecommunications chain for notifying specific individuals of an ...

  • mass notification system (MNS)

    A mass notification system is a platform that sends one-way messages to inform employees and the public of an emergency.

  • disaster recovery as a service (DRaaS)

    One approach to a strong disaster recovery plan is DRaaS, where companies offload data replication and restoration ...

SearchStorage

  • data migration

    Data migration is the process of transferring data between data storage systems, data formats or computer systems.

  • compact disc (CD)

    A compact disc is a portable storage medium that can be used for recording, storing and playing back audio, video and other data ...

  • secondary storage

    Secondary storage is used to protect inactive data written from a primary storage array to a nonvolatile tier of disk, flash or ...

SearchSolidStateStorage

  • SSD RAID (solid-state drive RAID)

    SSD RAID (solid-state drive RAID) is a methodology commonly used to protect data by distributing redundant data blocks across ...

  • Tier 0

    Tier 0 (tier zero) is a level of data storage that is faster, and perhaps more expensive, than any other level in the storage ...

  • PCIe SSD (PCIe solid-state drive)

    A PCIe SSD (PCIe solid-state drive) is a high-speed expansion card that attaches a computer to its peripherals.

SearchCloudStorage

  • RESTful API

    A RESTful application program interface breaks down a transaction to create a series of small modules, each of which addresses an...

  • cloud storage infrastructure

    Cloud storage infrastructure is the hardware and software framework that supports the computing requirements of a private or ...

  • Zadara VPSA and ZIOS

    Zadara Storage provides block, file or object storage with varying levels of compute and capacity through its ZIOS and VPSA ...

Close