Tagged Command Queuing (TCQ) is a technology built into certain ATA and SCSI[1] hard drives. It allows the operating system to send multiple read and write requests to a hard drive. ATA TCQ is not identical in function to the more efficient Native Command Queuing (NCQ) used by SATA drives.[2] SCSI TCQ does not suffer from the same limitations as ATA TCQ.
Without TCQ, an operating system was limited to sending one request at a time. To boost performance, the OS had to determine the order of the requests based on its own – possibly incorrect – perspective of the hard drive activity (otherwise known as I/O scheduling). With TCQ, the drive can make its own decisions about how to order the requests (and in turn relieve the operating system from having to do so). Thus TCQ can improve the overall performance of a hard drive if it is implemented correctly.
^in the form of Parallel SCSI, Serial attached SCSI, and Fibre Channel drives
TaggedCommandQueuing (TCQ) is a technology built into certain ATA and SCSI hard drives. It allows the operating system to send multiple read and write...
Taggedqueuing is a method for allowing a hardware device or controller to process commands received from a device driver out of order. It requires that...
in server-type applications. Native CommandQueuing was preceded by Parallel ATA's version of TaggedCommandQueuing (TCQ). ATA's attempt at integrating...
its queue using, for instance, the elevator algorithm to minimize the mechanical movement. Native CommandQueuing (NCQ) in Serial ATA (SATA) Tagged Command...
"overlapped feature set" and a "queued feature set" as optional features, both being given the name "TaggedCommandQueuing" (TCQ), a reference to a set...
command queuing and reordering commonly called either TaggedCommandQueuing (TCQ) or Native CommandQueuing (NCQ). Many consumer SATA HDDs either cannot do...
Storage is based on the SCSI architectural model and supports SCSI TaggedCommandQueuing. The standard is developed by, and available from, the JEDEC Solid...
Most SAS drives provide taggedcommandqueuing, while most newer SATA drives provide native commandqueuing. SATA uses a command set that is based on the...
Linux anticipatory scheduler may reduce performance on disks using TaggedCommandQueuing (TCQ), high performance disks, and hardware RAID arrays. An anticipatory...
portability. Some advanced hard disk drive commands, such as TaggedCommandQueuing and Native CommandQueuing (which may increase performance), ATA Secure...
over its predecessor was TaggedCommandQueuing, a feature that had previously been available only in SCSI drives. Commandqueuing resulted in a notable...
TCQ or tcq may refer to: TaggedCommandQueuing Coronel FAP Carlos Ciriani Santa Rosa International Airport (IATA code : TCQ) Kaiy language (ISO 639-3...
drives at the time, with 1.6 inches in height. They had TaggedCommandQueuing with up to 64 commands and a MTBF rating of 1.2 million hours, or 137 years...
allows the use of advanced features of SATA such as hotplug and native commandqueuing (NCQ). If AHCI is not enabled by the motherboard and chipset, SATA...
Completely Fair Queuing (CFQ) is an I/O scheduler for the Linux kernel which was written in 2003 by Jens Axboe. CFQ places synchronous requests submitted...
System Interface) commands as specified by IEEE Std 1003.1-2008, which is part of the Single UNIX Specification (SUS). These commands can be found on Unix...
of the native central queue scheduling algorithm in a symmetric multiprocessing operating system. Each item in the queue has a tag indicating its kin processor...
has extended tags further into a four bit tag. The microcode level that specified four bit tags was referred to as level Gamma. Even-tagged words are user...
These can be interrogated by a MODE SENSE command and set by a MODE SELECT command. The MODE SENSE commands and the mode page formats include a 6-bit...
text-only, etc. Parameters can also be hidden using a "secret" tag, or made mandatory. All commands in VOS are defined in full with underbars to separate words...
out an after-queue filtering setup with discarding or quarantining of messages, but leaves a possibility of delivering (possibly tagged) messages, or...
ALTQ queueing implementation for a number of queuing disciplines, notably RED and Blue. FreeBSD 11 included CoDel, PIE, FQ-CoDel and FQ-PIE queuing disciplines...
preview version Future release Source: Laravel [[Category:Wikipedia pages tagged for copyright problems|]] The following features serve as Laravel's key...
are applications for user interaction. Graphical user interface (GUI), command-line interface (CLI), Notification, Storage, etc are additional APIs for...
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