Automatic Acoustic Management
Encyclopedia
Automatic acoustic management (AAM) is a method for reducing acoustic emanations in AT Attachment
(ATA) mass storage
devices, such as ATA hard disk drives and ATAPI optical disc drives. AAM is an optional feature set for ATA/ATAPI devices; when a device supports AAM, the acoustic management parameters are adjustable through a software or firmware user interface
.
The ATA/ATAPI sub-command for setting the level of AAM operation is an 8-bit value from 0 to 255. Most modern drives ship with the vendor-defined value of 0x00 in the acoustic management setting. This often translates to the max-performance value of 254 stated in the standard. Values between 128 and 254 (0x80 - 0xFE) enable the feature and select most-quiet to most-performance settings along that range. Though hard drive manufacturers may support the whole range of values, the settings are allowed to be banded, so many values could provide the same acoustic performance.
Though there is no definition of the function implemented to provide acoustic management in the ATA standard, most drives use power control of the head-positioning servo to reduce vibration induced by the head positioning mechanism. Western Digital calls this InteliSeek(tm) which uses only enough head acceleration to position the head at the target track and sector "just in time" to access data. Previous seek mechanisms used maximum power and acceleration to position the head. This operation induced the familiar clicking vibration emanating from a seeking hard drive. Western Digital provides a demonstration flash movie illustrating just-in-time head positioning on their web site.
In order to provide best acoustic performance, some drive manufacturers may limit the maximum seek velocity of the heads for AAM operation. This degrades performance by increasing the average seek time: some head movements are forced to wait an additional disk rotation before accessing data because the head was unable to move to the target position during the first rotation due to velocity limits. For example, benchmark tests with SiSoftware Sandra Lite on a Samsung HD154UI (1.5TB, SATA300, 3.5", 5400rpm, 32MB Cache) hard drive showed no measurable performance impact for an AAM setting of 190, but the drive did become noticeably more quiet than the disabled setting (0). Selecting the most-quiet setting (128) caused average random access time to increase about 10% while quieting improved noticeably over the middle setting. On this drive, some quieting is available without performance impact, and even more quieting is available if some performance degradation is acceptable.
By contrast, a Western Digital WD1001FALS-00J7B0 (1TB, SATA300, 3.5", 7200rpm, 32MB Cache) disk drive shows a decrease from 18ms to 12.5ms by changing the value from 128 to 254, with little to no increase in noise. This drive did appear to be slightly less quiet than the Samsung in tests. Users should read manuals carefully for available settings of individual drives in each application.
AAM operates independently of advanced power management
settings. However, selecting lower head acceleration (quieter operation) uses less power, so energy-conscious users might prefer the most-quiet setting (128) for power management purposes.
INCITS (formerly NCITS) first standardized AAM in the ATA/ATAPI-6 specification.
AT Attachment
Parallel ATA , originally ATA, is an interface standard for the connection of storage devices such as hard disks, solid-state drives, floppy drives, and optical disc drives in computers. The standard is maintained by X3/INCITS committee...
(ATA) mass storage
Mass storage
In computing, mass storage refers to the storage of large amounts of data in a persisting and machine-readable fashion. Devices and/or systems that have been described as mass storage include tape libraries, RAID systems, hard disk drives, magnetic tape drives, optical disc drives, magneto-optical...
devices, such as ATA hard disk drives and ATAPI optical disc drives. AAM is an optional feature set for ATA/ATAPI devices; when a device supports AAM, the acoustic management parameters are adjustable through a software or firmware user interface
User interface
The user interface, in the industrial design field of human–machine interaction, is the space where interaction between humans and machines occurs. The goal of interaction between a human and a machine at the user interface is effective operation and control of the machine, and feedback from the...
.
The ATA/ATAPI sub-command for setting the level of AAM operation is an 8-bit value from 0 to 255. Most modern drives ship with the vendor-defined value of 0x00 in the acoustic management setting. This often translates to the max-performance value of 254 stated in the standard. Values between 128 and 254 (0x80 - 0xFE) enable the feature and select most-quiet to most-performance settings along that range. Though hard drive manufacturers may support the whole range of values, the settings are allowed to be banded, so many values could provide the same acoustic performance.
Though there is no definition of the function implemented to provide acoustic management in the ATA standard, most drives use power control of the head-positioning servo to reduce vibration induced by the head positioning mechanism. Western Digital calls this InteliSeek(tm) which uses only enough head acceleration to position the head at the target track and sector "just in time" to access data. Previous seek mechanisms used maximum power and acceleration to position the head. This operation induced the familiar clicking vibration emanating from a seeking hard drive. Western Digital provides a demonstration flash movie illustrating just-in-time head positioning on their web site.
In order to provide best acoustic performance, some drive manufacturers may limit the maximum seek velocity of the heads for AAM operation. This degrades performance by increasing the average seek time: some head movements are forced to wait an additional disk rotation before accessing data because the head was unable to move to the target position during the first rotation due to velocity limits. For example, benchmark tests with SiSoftware Sandra Lite on a Samsung HD154UI (1.5TB, SATA300, 3.5", 5400rpm, 32MB Cache) hard drive showed no measurable performance impact for an AAM setting of 190, but the drive did become noticeably more quiet than the disabled setting (0). Selecting the most-quiet setting (128) caused average random access time to increase about 10% while quieting improved noticeably over the middle setting. On this drive, some quieting is available without performance impact, and even more quieting is available if some performance degradation is acceptable.
By contrast, a Western Digital WD1001FALS-00J7B0 (1TB, SATA300, 3.5", 7200rpm, 32MB Cache) disk drive shows a decrease from 18ms to 12.5ms by changing the value from 128 to 254, with little to no increase in noise. This drive did appear to be slightly less quiet than the Samsung in tests. Users should read manuals carefully for available settings of individual drives in each application.
AAM operates independently of advanced power management
Advanced Power Management
Advanced power management is an API developed by Intel and Microsoft and released in 1992 which enables an operating system running an IBM-compatible personal computer to work with the BIOS to achieve power management.Revision 1.2 was the last version of the APM specification, released in 1996....
settings. However, selecting lower head acceleration (quieter operation) uses less power, so energy-conscious users might prefer the most-quiet setting (128) for power management purposes.
INCITS (formerly NCITS) first standardized AAM in the ATA/ATAPI-6 specification.
See also
- Device configuration overlayDevice configuration overlayDevice configuration overlay is a hidden area on many of today’s hard disk drives . Usually when information is stored in either the DCO or host protected area , it is not accessible by the BIOS, OS, or the user. However, certain tools can be used to modify the HPA or DCO...
- International Committee for Information Technology Standards
- Quiet PCQuiet PCA quiet PC is a personal computer that makes little noise. Common uses for quiet PCs include video editing, sound mixing, home servers, and home theater PCs. A typical quiet PC uses quiet cooling and storage devices and energy-efficient parts....
- S.M.A.R.T.
External links
- Argus Monitor, Comprehensive tool for HDD monitoring, includes functions for AAM parameter tuning (Windows). Accessed on 27 April 2011.
- HDDScan, an AAM tool for Windows. Accessed on 1 April 2009.
- hdparm, a Linux tool for reading and changing ATA drive parameters. Accessed on 1 April 2009.
- hdparm for Windows Accessed on 1 April 2009.
- Wegel, Alex. "Set Automatic Acoustic Management level on hard drives." MacOSXHints.com. 14 October 2004. Accessed on 1 April 2009.
- Flash demo of variable seek acceleration in hard drives accessed on 18 February 2010.