Intel Application Accelerator User's Manual

Advanced Host Controller Interface / Native Command Queuing

7 Advanced Host Controller

Interface / Native Command

Queuing

Advanced Host Controller Interface

Advanced Host Controller Interface (AHCI) is an interface specification that allows the storage

driver to enable advanced Serial ATA features such as Native Command Queuing and Native Hot

Plug.

Note: AHCI is built into the Intel® 915 and Intel® 925 Express Chipsets that use the Intel® 82801FR

I/O Controller Hub (ICH6R) and requires Intel® Application Accelerator version 4.0 or later.

Native Command Queuing

Native Command Queuing (NCQ) is a feature supported by AHCI, It allows Serial ATA hard

drives to accept more than one command at a time. NCQ, when used in conjunction with a hard

drive that supports NCQ, increases storage performance on random workloads by allowing the

drive to internally optimize the order of commands.

Note: In order to take advantage of NCQ, you need: Intel 915 or Intel 925 Express Chipset with the

ICH6R, Intel Application Accelerator version 4.0 or later, and a hard drive which supports NCQ.

Native Hot Plug

Native hot plug is a feature supported by AHCI, allowing Serial ATA hard drive removal or

insertion while the system is powered on and running. For example, this may be used when

replacing a failed hard drive that is in an externally-accessible drive enclosure.

Note: In order to take advantage of native hot plug, you need the following:

x Intel 915 or Intel 925 Express Chipset using ICH6R

x Intel Application Accelerator version 4.0 or later

x A hard drive which supports hot plug.

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