Advanced host controller interface

The Advanced Host Controller Interface ( AHCI ) is an open interface - Standard for Serial ATA - Controller . It makes it possible to communicate with these controllers via software.

With the help of the freely available specification, the development of drivers for Serial ATA devices is to be standardized and thus greatly simplified. There is no longer a need to develop a special Serial ATA driver for mainboards whose controller supports AHCI. Instead, for full support of devices such as B. hard drives only require an available, uniform AHCI driver.

The AHCI specification was developed by a working group led by Intel and published in 2004.

application

If the SATA Configuration BIOS setting for mainboards is set to AHCI, the connected hard disks are addressed with the support of Native Command Queuing (NCQ). As a result, pending commands are rearranged in order to execute them in the optimal order. In most cases, this increases the throughput of the hard disk by a few percent with several programs working in parallel with many scattered accesses.

Operating systems and compatibility

Many Unix- based operating systems such as Linux allow the setting in the BIOS to be changed even after installation.

With Microsoft Windows Vista , Windows 7 as well as Windows 8 , Windows 8.1 and currently Windows 10, if the system was installed in IDE mode, a key in the Windows registry must first be changed, otherwise a blue screen will appear. However, there is also the option of starting Windows in Safe Mode after switching from ATA to AHCI . The change is recognized and corrected in the system. Windows can then be started normally in the new mode. Windows XP does not natively support AHCI, but it can be activated during installation (with F6 and the driver on a data carrier). If Windows XP was installed in IDE mode, the driver can be installed afterwards, which is somewhat complicated. With Windows 2000, an AHCI driver can also be installed and used using the F6 method mentioned above.

Windows 2000 and XP also offer the option of integrating the AHCI driver into the installation medium using a technique known as slipstreaming (auxiliary programs for this nLite or Isobuster ). Windows loads the correct driver with the setup at the beginning of the installation. This method is particularly suitable for systems without a built-in floppy disk drive, because Windows 2000 and XP use the F6 method to search for the driver files only under drive letter A, which corresponds to the 3.5 " floppy disk drive ; installation CDs with XP-SP3 can use the Drivers can also be loaded from a USB floppy disk drive.

There is also an AHCI driver for eComStation (the further development of IBM's OS / 2 ).

Related interfaces

NVMe ( NVM Express , Non-Volatile Memory Host Controller Interface)

Web links

Individual evidence

↑ Switch Vista from IDE to AHCI

↑ Upgrade Windows XP to AHCI later (Intel ICHx) ( Memento of the original from February 25, 2010 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. @1@ 2
↑ Intel® Rapid Storage Technology No floppy disk drive for F6 installation method of the RAID driver under Windows XP http://www.intel.com/support/de/chipsets/imsm/sb/cs-029958.htm from Intel Support Germany
↑ http://hobbes.nmsu.edu/h-search.php?key=AHCI&pushbutton=Search

[1] Switch Vista from IDE to AHCI