 | This article needs additional citations for verification .(July 2011) |
Automatic acoustic management (AAM) is a method for reducing acoustic emanations in AT Attachment (ATA) mass storage devices for computer data storage, 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. [1]
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.
Although 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 IntelliSeek™ 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.
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.
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.
AAM is no longer available for Seagate and Western Digital drives. In 2008, Seagate removed AAM capabilities from all its drives because Convolve alleged that one of its patents, US Patent No. 6,314,473 covers AAM technology. Western Digital began doing the same in 2011, without making any official announcements, nor updating their product documentation. The product specification sheets continue to claim (in March 2012) that there are different seek modes on their drives. However the hardware that is now manufactured does not allow control over AAM.
Parallel ATA (PATA), originally AT Attachment, also known as IDE, is a standard interface designed for IBM PC-compatible computers. It was first developed by Western Digital and Compaq in 1986 for compatible hard drives and CD or DVD drives. The connection is used for storage devices such as hard disk drives, floppy disk drives, optical disc drives, and tape drives in computers.
A hard disk drive (HDD), hard disk, hard drive, or fixed disk, is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magnetic material. The platters are paired with magnetic heads, usually arranged on a moving actuator arm, which read and write data to the platter surfaces. Data is accessed in a random-access manner, meaning that individual blocks of data can be stored and retrieved in any order. HDDs are a type of non-volatile storage, retaining stored data when powered off. Modern HDDs are typically in the form of a small rectangular box.
The ST-506 and ST-412 were early hard disk drive products introduced by Seagate in 1980 and 1981 respectively, that later became construed as hard disk drive interfaces: the ST-506 disk interface and the ST-412 disk interface. Compared to the ST-506 precursor, the ST-412 implemented a refinement to the seek speed, and increased the drive capacity from 5 MB to 10 MB, but was otherwise highly similar.
CompactFlash (CF) is a flash memory mass storage device used mainly in portable electronic devices. The format was specified and the devices were first manufactured by SanDisk in 1994.
Disk formatting is the process of preparing a data storage device such as a hard disk drive, solid-state drive, floppy disk, memory card or USB flash drive for initial use. In some cases, the formatting operation may also create one or more new file systems. The first part of the formatting process that performs basic medium preparation is often referred to as "low-level formatting". Partitioning is the common term for the second part of the process, dividing the device into several sub-devices and, in some cases, writing information to the device allowing an operating system to be booted from it. The third part of the process, usually termed "high-level formatting" most often refers to the process of generating a new file system. In some operating systems all or parts of these three processes can be combined or repeated at different levels and the term "format" is understood to mean an operation in which a new disk medium is fully prepared to store files. Some formatting utilities allow distinguishing between a quick format, which does not erase all existing data and a long option that does erase all existing data.
Seagate Technology Holdings plc is an American data storage company. It was incorporated in 1978 as Shugart Technology and commenced business in 1979. Since 2010, the company has been incorporated in Dublin, Ireland, with operational headquarters in Fremont, California, United States.
Logical block addressing (LBA) is a common scheme used for specifying the location of blocks of data stored on computer storage devices, generally secondary storage systems such as hard disk drives. LBA is a particularly simple linear addressing scheme; blocks are located by an integer index, with the first block being LBA 0, the second LBA 1, and so on.
Self-Monitoring, Analysis, and Reporting Technology is a monitoring system included in computer hard disk drives (HDDs) and solid-state drives (SSDs). Its primary function is to detect and report various indicators of drive reliability with the intent of anticipating imminent hardware failures.
The USB mass storage device class is a set of computing communications protocols, specifically a USB Device Class, defined by the USB Implementers Forum that makes a USB device accessible to a host computing device and enables file transfers between the host and the USB device. To a host, the USB device acts as an external hard drive; the protocol set interfaces with a number of storage devices.
The Microdrive is a type of miniature, 1-inch hard disks produced by IBM and Hitachi. These rotational media storage devices were designed to fit in CompactFlash (CF) Type II slots.
In computing, a hybrid drive is a logical or physical storage device that combines a faster storage medium such as solid-state drive (SSD) with a higher-capacity hard disk drive (HDD). The intent is adding some of the speed of SSDs to the cost-effective storage capacity of traditional HDDs. The purpose of the SSD in a hybrid drive is to act as a cache for the data stored on the HDD, improving the overall performance by keeping copies of the most frequently used data on the faster SSD drive.
hdparm is a command line program for Linux to set and view ATA hard disk drive hardware parameters and test performance. It can set parameters such as drive caches, sleep mode, power management, acoustic management, and DMA settings. GParted and Parted Magic both include hdparm.
In 1953, IBM recognized the immediate application for what it termed a "Random Access File" having high capacity and rapid random access at a relatively low cost. After considering technologies such as wire matrices, rod arrays, drums, drum arrays, etc., the engineers at IBM's San Jose California laboratory invented the hard disk drive. The disk drive created a new level in the computer data hierarchy, then termed Random Access Storage but today known as secondary storage, less expensive and slower than main memory but faster and more expensive than tape drives.
A solid-state drive (SSD) is a solid-state storage device that uses integrated circuit assemblies to store data persistently, typically using flash memory, and functions as secondary storage in the hierarchy of computer storage. It is also sometimes called a semiconductor storage device, a solid-state device, or a solid-state disk, even though SSDs lack the physical spinning disks and movable read-write heads used in hard disk drives (HDDs) and floppy disks. SSD also has rich internal parallelism for data processing.
The host protected area (HPA) is an area of a hard drive or solid-state drive that is not normally visible to an operating system. It was first introduced in the ATA-4 standard CXV (T13) in 2001.
In computing, error recovery control (ERC) is a feature of hard disks which allow a system administrator to configure the amount of time a drive's firmware is allowed to spend recovering from a read or write error. Limiting the recovery time allows for improved error handling in hardware or software RAID environments. In some cases, there is a conflict as to whether error handling should be undertaken by the hard drive or by the RAID implementation, which leads to drives being marked as unusable and significant performance degradation, when this could otherwise have been avoided.
Hardware-based full disk encryption (FDE) is available from many hard disk drive (HDD/SSD) vendors, including: Hitachi, Integral Memory, iStorage Limited, Micron, Seagate Technology, Samsung, Toshiba, Viasat UK, Western Digital. The symmetric encryption key is maintained independently from the computer's CPU, thus allowing the complete data store to be encrypted and removing computer memory as a potential attack vector.
The Seagate Barracuda is a series of hard disk drives and later solid state drives produced by Seagate Technology that was first introduced in 1993.
Higher performance in hard disk drives comes from devices which have better performance characteristics. These performance characteristics can be grouped into two categories: access time and data transfer time.
Shingled magnetic recording (SMR) is a magnetic storage data recording technology used in hard disk drives (HDDs) to increase storage density and overall per-drive storage capacity. Conventional hard disk drives record data by writing non-overlapping magnetic tracks parallel to each other, while shingled recording writes new tracks that overlap part of the previously written magnetic track, leaving the previous track narrower and allowing higher track density. Thus, the tracks partially overlap similar to roof shingles. This approach was selected because, if the writing head is made too narrow, it cannot provide the very high fields required in the recording layer of the disk.