Native Command Queuing Last modified: Thursday, November 18, 2004
Native Command Queuing (NCQ) is a command protocol in Serial ATA that can be implemented only on native Serial ATA hard drives. It allows multiple commands to be outstanding within a drive at the same time. Drives that support NCQ have an internal queue where outstanding commands can be dynamically rescheduled or re-ordered, along with the necessary tracking mechanisms for outstanding and completed portions of the workload. NCQ also has a mechanism that allows the host to issue additional commands to the drive while the drive is seeking data for another command. NCQ allows the drive to set up the direct memory access (DMA) operation for a data transfer without host software intervention. This is also called first-party DMA - it means that the device is capable of complex sequences of operations without CPU intervention. The drive itself knows the current angular and rotational position of the drive head. The drive then selects the next data transfer to minimize both seek and rotational latencies. * [Definition Source: Seagate Technology]
•E-mail this definition to a colleague• For internet.com pages about Native Command Queuing . Also check out the following links! Serial ATA Native Command Queuing (PDF)  A joint whitepaper by Intel Corporation and Seagate Technology. Serial ATA.org  The Serial ATA International Organization (SATA-IO) is an independent, non-profit organization developed by and for leading industry companies.	Disk Drives Hardware Ports and Interfaces ATA Serial ATA Give Us Your Feedback Native Command Queuing Products : Top Store Offers: ISSI Data  97.50Serial ATA Hard Drive maximize the performance of HP Workstations by providing the technologies to meet your increasing storage demands. This high-cap... PC Connection  162.00This is an HP 250GB SATA 3.0 Gbps Hard Drive with Native Command Queuing. It features a 7200rpm spindle speed. onSale  565.99SATA drives are our standard high bandwidth hard drive storage options; select models are also available with high performance 10K rpm rotation speeds... ISSI Data  158.66Serial ATA Hard Drive maximize the performance of HP Workstations by providing the technologies to meet your increasing storage demands. This high-cap... CompUSA.com  299.99HP hard disk drives undergo an intense qualification process that eliminates data integrity problems, firmware and O/S incompatibilities. Compare all matches: 4 Store Offers