Native Command Queuing (NCQ)

Definition - What does Native Command Queuing (NCQ) mean?

Native command queuing (NCQ) is a technology enabling SATA hard drives to accept more than one command at a time by optimizing the order in which read and write commands are executed. This increases the performance of the drive by limiting the number of drive head movements when multiple read/write requests are queued.

Techopedia explains Native Command Queuing (NCQ)

NCQ replaces tagged command queuing (TCQ), which is used with parallel ATA (PATA). The manner in which TCQ interacts with the operating system (OS) taxes the CPU in return for little performance gain.

Both in the hard drive and in the SATA host bus adapter, NCQ must be supported and enabled and the proper driver must be loaded into the OS. Some OSs include the required generic drivers (such as Windows Vista and Windows 7) whereas others require vendor-specific drivers to be loaded to enable NCQ, like Windows XP.

NCQ may also be used in solid-state drives (SSDs), drives containing data in non-volatile memory chips and contain no moving parts. Here, latency (the delay in processing commands) is found on the host not on the drive. The drive uses NCQ to ensure it has commands to process while the host adapter is processing CPU tasks.

Posted by:

Connect with us

Techopedia on Linkedin
Techopedia on Linkedin
Tweat cdn.techopedia.com
Techopedia on Twitter


'@Techopedia'
Sign up for Techopedia's Free Newsletter!
Techwise Webinar Series
Understanding the Big Data Landscape
Understanding the Big Data Landscape
Big Data is everywhere, that's for sure. But the big question for today's savvy enterprise is: exactly where does Big Data fit into your organization?

Email Newsletter

Join 138,000+ IT pros on our weekly newsletter

Resources
Free Whitepaper – Bridging the IT Operations Application Owner Gap
Free Whitepaper – Bridging the IT Operations Application Owner Gap:
Conflicting organizational needs all too often create tension between functional silos. Application owners demand more and more resources.
Free 30 Day Trial – VMTurbo Operations Manager
Free 30 Day Trial – VMTurbo Operations Manager:
VMTurbo's flagship product, Operations Manager maintains your virtual and cloud environments in a healthy state. It manages homogeneous and...