571:(the number of bits that can be stored in a certain area of the disk) has been increased over time by increasing both the number of tracks across the disk, and the number of sectors per track. The latter will increase the data transfer rate for a given RPM speed. Improvement of data transfer rate performance is correlated to the areal density only by increasing a track's linear surface bit density (sectors per track). Simply increasing the number of tracks on a disk can affect seek times but not gross transfer rates. According to industry observers and analysts for 2011 to 2016, “The current roadmap predicts no more than a 20%/yr improvement in bit density”. Seek times have not kept up with throughput increases, which themselves have not kept up with growth in bit density and storage capacity.
110:) and there is an actuator with an arm that suspends a head that can transfer data with that media. When the drive needs to read or write a certain sector it determines in which track the sector is located. It then uses the actuator to move the head to that particular track. If the initial location of the head was the desired track then the seek time would be zero. If the initial track was the outermost edge of the media and the desired track was at the innermost edge then the seek time would be the maximum for that drive. Seek times are not linear compared with the seek distance traveled because of factors of acceleration and deceleration of the actuator arm.
626:
destination only just in time to read the sector, rather than arriving as quickly as possible and then having to wait for the sector to come around (i.e. the rotational latency). Many of the hard drive companies are now producing Green Drives that require much less power and cooling. Many of these Green Drives spin slower (<5,400 rpm compared to 7,200, 10,000 or 15,000 rpm) thereby generating less heat. Power consumption can also be reduced by parking the drive heads when the disk is not in use reducing friction, adjusting spin speeds, and disabling internal components when not in use.
447:
580:
690:
724:(SMR) differ significantly in write performance characteristics from conventional (CMR) drives. In particular, sustained random writes are significantly slower on SMR drives. As SMR technology causes a degradation on write performance, some new HDD with Hybrid SMR technology (making it possible to adjust the ratio of SMR part and CMR part dynamically) may have various characteristics under different SMR/CMR ratios.
37:
387:). Most hard disk drives today support some form of power management which uses a number of specific power modes that save energy by reducing performance. When implemented, an HDD will change between a full power mode to one or more power saving modes as a function of drive usage. Recovery from the deepest mode, typically called Sleep where the drive is stopped or
152:. The track-to-track measurement is the time required to move from one track to an adjacent track. This is the shortest (fastest) possible seek time. In HDDs this is typically between 0.2 and 0.8 ms. The full stroke measurement is the time required to move from the outermost track to the innermost track. This is the longest (slowest) possible seek time.
509:" data transfer rate up to 1030 Mbit/s. This rate depends on the track location, so it will be higher on the outer zones (where there are more data sectors per track) and lower on the inner zones (where there are fewer data sectors per track); and is generally somewhat higher for 10,000 RPM drives.
616:
has become increasingly important, not only in mobile devices such as laptops but also in server and desktop markets. Increasing data center machine density has led to problems delivering sufficient power to devices (especially for spin up), and getting rid of the waste heat subsequently produced, as
597:
Sector interleave is a mostly obsolete device characteristic related to data rate, dating back to when computers were too slow to be able to read large continuous streams of data. Interleaving introduced gaps between data sectors to allow time for slow equipment to get ready to read the next block of
470:
of a drive will be the lower of the sustained internal and sustained external rates. The sustained rate is less than or equal to the maximum or burst rate because it does not have the benefit of any cache or buffer memory in the drive. The internal rate is further determined by the media rate, sector
362:
Another wrinkle occurs depending on whether surface bit densities are constant. Usually, with a CAV spin rate, the densities are not constant so that the long outside tracks have the same number of bits as the shorter inside tracks. When the bit density is constant, outside tracks have more bits than
203:
offers a set of features in some drives called Sound
Barrier Technology that include some user or system controlled noise and vibration reduction capability. Shorter seek times typically require more energy usage to quickly move the heads across the platter, causing loud noises from the pivot bearing
755:
that are smaller (2K, 4K, 8K, or 16K) than the blocks of data managed by the SSD (from 256 KB to 4 MB, hence 128 to 256 pages per block), over time, an SSD's write performance can degrade as the drive becomes full of pages which are partial or no longer needed by the file system. This can
163:
is a term used in enterprise storage environments to describe an HDD that is purposely restricted in total capacity so that the actuator only has to move the heads across a smaller number of total tracks. This limits the maximum distance the heads can be from any point on the drive thereby reducing
555:
is a procedure used to minimize delay in retrieving data by moving related items to physically proximate areas on the disk. Some computer operating systems perform defragmentation automatically. Although automatic defragmentation is intended to reduce access delays, the procedure can slow response
601:
However, because interleaving introduces intentional physical delays between blocks of data thereby lowering the data rate, setting the interleave to a ratio higher than required causes unnecessary delays for equipment that has the performance needed to read sectors more quickly. The interleaving
496:
Additional time required to move to the first track of the next cylinder and begin reading; the name cylinder is used because typically all the tracks of a drive with more than one head or data surface are read before moving the actuator. This time is typically about twice the track-to-track seek
660:
Most hard disk drives today support some form of power management which uses a number of specific power modes that save energy by reducing performance. When implemented an HDD will change between a full power mode to one or more power saving modes as a function of drive usage. Recovery from the
625:
increase at higher drive temperatures. Similar issues exist for large companies with thousands of desktop PCs. Smaller form factor drives often use less power than larger drives. One interesting development in this area is actively controlling the seek speed so that the head arrives at its
629:
Drives use more power, briefly, when starting up (spin-up). Although this has little direct effect on total energy consumption, the maximum power demanded from the power supply, and hence its required rating, can be reduced in systems with several drives by controlling when they spin up.
60:. It is composed of a few independently measurable elements that are added together to get a single value when evaluating the performance of a storage device. The access time can vary significantly, so it is typically provided by manufacturers or measured in benchmarks as an average.
117:
is the average of all possible seek times which technically is the time to do all possible seeks divided by the number of all possible seeks, but in practice it is determined by statistical methods or simply approximated as the time of a seek over one-third of the number of tracks.
462:) covers both the internal rate (moving data between the disk surface and the controller on the drive) and the external rate (moving data between the controller on the drive and the host system). The measurable data transfer rate will be the lower (slower) of the two rates. The
883:
535:
A current widely used standard for the "buffer-to-computer" interface is 3.0 Gbit/s SATA, which can send about 300 megabyte/s (10-bit encoding) from the buffer to the computer, and thus is still comfortably ahead of today's disk-to-buffer transfer rates.
204:
and greater device vibrations as the heads are rapidly accelerated during the start of the seek motion and decelerated at the end of the seek motion. Quiet operation reduces movement speed and acceleration rates, but at a cost of reduced seek performance.
337:
Therefore, the rotational latency and resulting access time can be improved (decreased) by increasing the rotational speed of the disks. This also has the benefit of improving (increasing) the throughput (discussed later in this article).
564:
HDD data transfer rate depends upon the rotational speed of the disks and the data recording density. Because heat and vibration limit rotational speed, increasing density has become the main method to improve sequential transfer rates.
374:
has become increasingly important, not only in mobile devices such as laptops but also in server and desktop markets. Increasing data center machine density has led to problems delivering sufficient power to devices (especially for
97:
measures the time it takes the head assembly on the actuator arm to travel to the track of the disk where the data will be read or written. The data on the media is stored in sectors which are arranged in parallel circular tracks
363:
inside tracks and is generally combined with a CLV spin rate. In both these schemes contiguous bit transfer rates are constant. This is not the case with other schemes such as using constant bit density with a CAV spin rate.
598:
data. Without interleaving, the next logical sector would arrive at the read/write head before the equipment was ready, requiring the system to wait for another complete disk revolution before reading could be performed.
649:(PUIS): each drive does not spin up until the controller or system BIOS issues a specific command to do so. This allows the system to be set up to stagger disk start-up and limit maximum power demand at switch-on.
748:
Measurement of seek time is only testing electronic circuits preparing a particular location on the memory in the storage device. Typical SSDs will have a seek time between 0.08 and 0.16 ms.
415:
is the time it takes for the drive electronics to set up the necessary communication between the various components in the device so it can read or write the data. This is of the order of 3
490:
Additional time required to electrically switch from one head to another, re-align the head with the track and begin reading; only applies to multi-head drive and is about 1 to 2 ms.
673:
that parks the disk heads if the machine is dropped, hopefully before impact, to offer the greatest possible chance of survival in such an event. Maximum shock tolerance to date is 350
484:
Additional time (bytes between sectors) needed for control structures and other information necessary to manage the drive, locate and validate data and perform other support functions.
395:
that include some additional features that do reduce power, but can adversely affect the latency including lower spindle speeds and parking heads off the media to reduce friction.
1369:
In some early PCs the internal bus was slower than the drive data rate so sectors would be missed resulting in the loss of an entire revolution. To prevent this sectors were
602:
ratio was therefore usually chosen by the end-user to suit their particular computer system's performance capabilities when the drive was first installed in their system.
126:
The first HDD had an average seek time of about 600 ms. and by the middle 1970s, HDDs were available with seek times of about 25 ms. Some early PC drives used a
141:. Some mobile devices have 15 ms drives, with the most common mobile drives at about 12 ms and the most common desktop drives typically being around 9 ms.
539:
SSDs do not have the same internal limits of HDDs, so their internal and external transfer rates are often maximizing the capabilities of the drive-to-host interface.
1912:
1426:
833:
505:
According to vendor specifications sustained transfer rates up to 204 MB/s are available. As of 2010, a typical 7,200 RPM desktop HDD has a "disk-to-
1595:
391:, may take as long as several seconds to be fully operational thereby increasing the resulting latency. The drive manufacturers are also now producing
745:
are not applicable in measuring their performance, but they are affected by some electrically based elements that causes a measurable access delay.
1770:
1559:
1204:
1121:
1095:
1070:
764:. Flash memory wears out over time as it is repeatedly written to; the writes required by defragmentation wear the drive for no speed advantage.
501:
Data transfer rate (read/write) can be measured by writing a large file to disk using special file generator tools, then reading back the file.
1811:
1533:
1452:
438:. This time is usually very small, typically less than 100 ÎĽs, and modern HDD manufacturers account for it in their seek time specifications.
1854:
1284:
1478:
858:
164:
its average seek time, but also restricts the total capacity of the drive. This reduced seek time enables the HDD to increase the number of
196:) to reduce audible clicks and crunching sounds. Drives in smaller form factors (e.g. 2.5 inch) are often quieter than larger drives.
1326:
966:
605:
Modern technology is capable of reading data as fast as it can be obtained from the spinning platters, so interleaving is no longer used.
304:
is typically based on the empirical relation that the average latency in milliseconds for such a drive is one-half the rotational period.
1301:
1147:
917:
20:
comes from devices which have better performance characteristics. These performance characteristics can be grouped into two categories:
351:(CLV), used mainly in optical storage, varies the rotational speed of the optical disc depending upon the position of the head, and 2)
1795:
56:. The factors that control this time on a rotating drive are mostly related to the mechanical nature of the rotating disks and moving
1504:
199:
Some desktop- and laptop-class disk drives allow the user to make a trade-off between seek performance and drive noise. For example,
2066:
807:
1650:
1752:
1172:
567:
1696:
134:
type actuation in the 1980s, reducing seek times to around 20 ms. Seek time has continued to improve slowly over time.
1909:
1430:
1373:
to slow the effective data rate preventing missed sectors. This is no longer a problem for current PCs and storage devices.
2076:
1583:
193:
1996:
1955:
670:
1929:
1384:
1370:
1039:
721:
168:
available from the drive. The cost and power per usable byte of storage rises as the maximum track range is reduced.
2022:
674:
446:
2071:
1743:
548:
352:
1603:
761:
348:
57:
130:
to move the heads, and as a result had seek times as slow as 80–120 ms, but this was quickly improved by
992:
579:
656:, allowing the computer to spin up the drives in sequence to reduce load on the power supply when booting.
297:
181:
646:
1778:
1563:
1125:
1015:
634:
On SCSI hard disk drives, the SCSI controller can directly control spin up and spin down of the drives.
1753:
UNESCO International
Conference, Memory of the World in the Digital Age: Digitization and Preservation
1099:
1074:
788:
1233:
1815:
1537:
1252:
752:
2036:
1874:
1675:
1599:
419:, very much less than other overhead times, so it is usually ignored when benchmarking hardware.
312:
time (as the relevant part of the disk may have just passed the head when the request arrived).
200:
1888:
1846:
1456:
1405:
1333:
1949:
1850:
1280:
1274:
921:
742:
738:
733:
613:
371:
356:
53:
1482:
862:
757:
653:
1792:
1742:
Rosenthal, David S.H.; Rosenthal, Daniel C.; Miller, Ethan L.; Adams, Ian F. (2012-09-28).
970:
1916:
1799:
1305:
1211:
1176:
618:
583:
Low-level formatting software from 1987 to find highest performance interleave choice for
552:
384:
293:
17:
192:, lower rotational speeds (usually 5,400 rpm) and reduce the seek speed under load (
1718:
1839:
1584:
https://www.seagate.com/files/docs/pdf/datasheet/disc/cheetah-15k.7-ds1677.3-1007us.pdf
942:
1970:
1508:
1180:
689:
669:
Shock resistance is especially important for mobile devices. Some laptops now include
523:" data transfer rates varies amongst families of Optical disk drives with the slowest
516:" data transfer rates that are one or two orders of magnitude lower than that of HDDs.
2060:
189:
127:
359:, spins the media at one constant speed regardless of where the head is positioned.
63:
The key components that are typically added together to obtain the access time are:
52:
of a rotating drive is a measure of the time it takes before the drive can actually
778:
751:
Flash memory-based SSDs do not need defragmentation. However, because file systems
638:
622:
621:). Heat dissipation is tied directly to power consumption, and as drives age, disk
342:
107:
808:"Hard Disk (Hard Drive) Performance – transfer rates, latency and seek times"
383:
subsequently produced, as well as environmental and electrical cost concerns (see
36:
1357:
520:
513:
506:
416:
289:
177:
138:
1046:
2000:
642:
380:
347:
The spindle motor speed can use one of two types of disk rotation methods: 1)
131:
99:
1148:"Western Digital's New VelociRaptor VR200M: 10K RPM at 450GB and 600GB"
741:(SSDs) do not have moving parts. Most attributes related to the movement of
292:
under the read-write head. It depends on the rotational speed of a disk (or
1625:
661:
deepest mode, typically called Sleep, may take as long as several seconds.
1812:"Hitachi Unveils Energy-Efficient Hard Drive with Variable Spindle Speed"
1699:(Press release). IHSi iSuppli Research. storagenewsletter.com. 2012-05-24
586:
285:
185:
137:
The fastest high-end server drives today have a seek time around 4
528:
388:
376:
309:
1771:"Hard Disk Drive Power Consumption Measurements: X-bit's Methodology"
524:
103:
478:
Rate at which the drive can read bits from the surface of the media.
434:
on the target track and stop vibrating so they do not read or write
355:(CAV), used in HDDs, standard FDDs, a few optical disc systems, and
578:
445:
35:
180:, audible noise is significant for certain applications, such as
783:
773:
165:
40:
A hard disk head on an access arm resting on a hard disk platter
834:"Red Hat Documentation: Hard Drive Performance Characteristics"
1930:"Surreptitiously Swapping SMR into Hard Drive Lines Must Stop"
1841:
Green tech: how to plan and implement sustainable IT solutions
684:
1356:
In the 1950s and 1960s magnetic data storage devices used a
1205:"Understanding Solid State Drives (part two – performance)"
734:
Solid-state drive § Comparison with other technologies
471:
overhead time, head switch time, and cylinder switch time.
1997:"To Defrag or Not to Defrag–That Is the Question for SSD"
527:
at 1.23 Mbit/s floppy-like while a high performance
308:
is the time it takes to do a full rotation excluding any
144:
Two other less commonly referenced seek measurements are
1875:"Hitachi Deskstar 7K500 500GB HDD: As fast as it's big?"
1276:
The
Essentials of Computer Organization and Architecture
617:
well as environmental and electrical cost concerns (see
1651:"Turning Off Disk Defragmenter May Solve a Sluggish PC"
1527:
1525:
701:
531:
at 432 Mbit/s approaches the performance of HDDs.
450:
A plot showing dependency of transfer rate on cylinder
652:
Some SATA II and later hard disk drives support
1122:"IBM Archives – IBM 3350 direct access storage"
1279:. Jones & Bartlett Learning. pp. 499–500.
1889:"Adaptive Power Management for Mobile Hard Drives"
1838:
1406:"Adaptive Power Management for Mobile Hard Drives"
1719:"HDD Opportunities & Challenges, Now to 2020"
943:"What is Seek Time? - Definition from Techopedia"
852:
850:
300:(RPM). For most magnetic media-based drives, the
1814:. Xbitlabs.com. 22 October 2007. Archived from
1071:"IBM Archives – IBM 350 disk storage unit"
960:
958:
956:
1427:"Momentus 5400.5 SATA 3Gb/s 320-GB Hard Drive"
1273:Null, Linda; Lobur, Julia (14 February 2014).
1253:"Accelerate Your Hard Drive By Short Stroking"
1234:"Accelerate Your Hard Drive By Short Stroking"
1173:"WD Scorpio Blue Mobile: Drive Specifications"
912:
910:
908:
906:
904:
902:
900:
497:time. As of 2001, it was about 2 to 3 ms.
677:for operating and 1,000 g for non-operating.
556:when performed while the computer is in use.
172:Effect of audible noise and vibration control
8:
1910:Momentus 5400.5 SATA 3Gb/s 320-GB Hard Drive
77:
1837:Webber, Lawrence; Wallace, Michael (2009).
1251:Schmid, Patrick; Roos, Achim (2009-03-05).
512:Floppy disk drives have sustained "disk-to-
1936:. The 2-minute SMR and Industry Background
1745:The Economics of Long-Term Digital Storage
1697:"HDD Areal Density Doubling in Five Years"
1014:Chris Ruemmler; John Wilkes (March 1994).
211:
1199:
1197:
1096:"IBM Archives: IBM 350 disk storage unit"
993:"Hard Disk Tracks, Cylinders and Sectors"
1016:"An introduction to disk drive modeling"
920:. New York Data Recovery. Archived from
828:
826:
824:
799:
72:
25:
1947:
1124:. IBM. 23 January 2003. Archived from
1073:. IBM. 23 January 2003. Archived from
1505:"Transfer Performance Specifications"
991:Kozierok, Charles (18 January 2019).
7:
1327:"Seagate's Sound Barrier Technology"
760:command from the system or internal
1769:Artamonov, Oleg (6 December 2007).
1385:"Calculate IOPS in a storage array"
918:"Hard Drive Data Recovery Glossary"
547:Transfer rate can be influenced by
367:Effect of reduced power consumption
1873:Trusted Reviews (31 August 2005).
1146:Anand Lal Shimpi (April 6, 2010).
430:is the time it takes the heads to
288:of the disk to bring the required
14:
2023:"How do SSDS Work? - ExtremeTech"
1999:. rtcmagazine.com. Archived from
1098:. 23 January 2003. Archived from
1040:"Definition of Average Seek time"
1674:Kozierok, Charles (2001-04-17).
1558:Kozierok, Charles (2001-04-17).
1532:Kozierok, Charles (2001-04-17).
1503:Kozierok, Charles (2001-04-17).
1477:Kozierok, Charles (2001-04-17).
1451:Kozierok, Charles (2001-04-17).
1300:Kozierok, Charles (2001-04-17).
965:Kozierok, Charles (2001-04-17).
857:Kozierok, Charles (2001-04-17).
728:Comparison to solid-state drives
688:
645:(SATA) hard disk drives support
188:. Low noise disks typically use
122:Seek times & characteristics
82:
21:
1995:Lee, Yu Hsuan (December 2008).
1969:Brendan, Collins (2017-11-13).
1928:Kennedy, Patrick (2020-04-26).
1332:. November 2000. Archived from
284:) is the delay waiting for the
1021:. Hewlett-Packard Laboratories
184:, digital audio recording and
67:
1:
1562:. pcguide.com. Archived from
1536:. pcguide.com. Archived from
1507:. pcguide.com. Archived from
1481:. pcguide.com. Archived from
1455:. pcguide.com. Archived from
1304:. pcguide.com. Archived from
969:. pcguide.com. Archived from
861:. pcguide.com. Archived from
551:and the layout of the files.
2037:"Sustaining SSD Performance"
671:active hard drive protection
464:sustained data transfer rate
26:data transfer time (or rate)
1758:. UNESCO. pp. 513–528.
1649:Broida, Rick (2009-04-10).
1624:Kearns, Dave (2001-04-18).
1179:. June 2010. Archived from
722:shingled magnetic recording
343:Disk storage § CAV-CLV
262:
254:
246:
238:
230:
2093:
1383:Lowe, Scott (2010-02-12).
884:"Getting the hang of IOPS"
731:
379:), and getting rid of the
340:
306:Maximum rotational latency
302:average rotational latency
93:With rotating drives, the
549:file system fragmentation
353:constant angular velocity
2067:Computer storage devices
1954:: CS1 maint: location (
458:of a drive (also called
349:constant linear velocity
1791:e.g. Western Digital's
1453:"Command Overhead Time"
560:Effect of areal density
519:The sustained "disk-to-
407:command processing time
78:Command processing time
1717:Dave Anderson (2013).
1596:"Speed Considerations"
1560:"Cylinder switch Time"
1360:instead of flat discs.
594:
451:
298:revolutions per minute
41:
16:Higher performance in
1302:"Noise and Vibration"
743:mechanical components
720:Hard drives that use
582:
543:Effect of file system
449:
341:Further information:
332:= 0.5*Maximum latency
39:
2077:Computer peripherals
1971:"Dynamic Hybrid SMR"
1606:on 20 September 2011
789:Standard RAID levels
756:be ameliorated by a
493:Cylinder switch time
481:Sector overhead time
468:sustained throughput
213:Typical HDD figures
1975:WesternDigital BLOG
1781:on 16 October 2012.
1128:on January 21, 2005
753:write pages of data
739:Solid-state devices
647:power-up in standby
357:vinyl audio records
214:
113:A rotating drive's
106:depending upon the
1915:2010-11-29 at the
1845:. AMACOM. p.
1798:2012-11-18 at the
1534:"Head switch Time"
1387:. techrepublic.com
1255:. tomshardware.com
1214:. October 27, 2008
762:garbage collection
700:. You can help by
595:
456:data transfer rate
452:
442:Data transfer rate
276:(sometimes called
274:Rotational latency
212:
208:Rotational latency
73:Rotational latency
42:
2003:on April 24, 2011
1891:. Almaden.ibm.com
1861:green disk drive.
1856:978-0-8144-1446-0
1818:on 17 August 2012
1775:Xbit Laboratories
1286:978-1-284-15077-3
810:. pctechguide.com
718:
717:
654:staggered spin-up
614:Power consumption
609:Power consumption
529:12x Blu-ray drive
372:Power consumption
271:
270:
115:average seek time
2084:
2072:Hard disk drives
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1777:. Archived from
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1602:. Archived from
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1429:. Archived from
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1109:
1107:
1102:on April 9, 2005
1092:
1086:
1085:
1083:
1082:
1077:on April 9, 2005
1067:
1061:
1060:
1058:
1057:
1051:
1045:. Archived from
1044:
1036:
1030:
1029:
1027:
1026:
1020:
1011:
1005:
1004:
1002:
1000:
988:
982:
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962:
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939:
933:
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929:
914:
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874:
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854:
845:
844:
842:
841:
830:
819:
818:
816:
815:
804:
713:
710:
692:
685:
665:Shock resistance
592:
589:
487:Head switch time
428:
427:
413:command overhead
409:
408:
278:rotational delay
215:
18:hard disk drives
2092:
2091:
2087:
2086:
2085:
2083:
2082:
2081:
2057:
2056:
2055:
2045:
2043:
2039:
2035:
2034:
2030:
2021:
2020:
2016:
2006:
2004:
1994:
1993:
1989:
1979:
1977:
1968:
1967:
1963:
1946:
1939:
1937:
1927:
1926:
1922:
1917:Wayback Machine
1908:
1904:
1894:
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1887:
1886:
1882:
1872:
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1867:
1857:
1836:
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1800:Wayback Machine
1790:
1786:
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1748:
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1721:
1716:
1715:
1711:
1702:
1700:
1695:
1694:
1690:
1681:
1679:
1676:"Areal Density"
1673:
1672:
1668:
1659:
1657:
1648:
1647:
1643:
1634:
1632:
1626:"How to defrag"
1623:
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1240:. 5 March 2009.
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1186:
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1177:Western Digital
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848:
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832:
831:
822:
813:
811:
806:
805:
801:
797:
770:
736:
730:
714:
708:
705:
698:needs expansion
683:
667:
619:green computing
611:
593:hard disk drive
590:
584:
577:
562:
553:Defragmentation
545:
444:
425:
424:
406:
405:
401:
385:green computing
369:
345:
328:Average latency
318:Maximum latency
296:), measured in
226:
224:
219:
210:
186:quiet computers
174:
158:
124:
91:
34:
12:
11:
5:
2090:
2088:
2080:
2079:
2074:
2069:
2059:
2058:
2054:
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2028:
2014:
1987:
1961:
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1880:
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1397:
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1318:
1292:
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1243:
1238:Tom's Hardware
1225:
1193:
1164:
1138:
1113:
1087:
1062:
1031:
1006:
995:. The PC Guide
983:
952:
947:Techopedia.com
934:
896:
875:
846:
820:
798:
796:
793:
792:
791:
786:
781:
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769:
766:
732:Main article:
729:
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682:
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244:
241:
237:
236:
233:
229:
228:
221:
209:
206:
190:fluid bearings
173:
170:
161:Short stroking
157:
156:Short stroking
154:
146:track-to-track
123:
120:
90:
87:
86:
85:
80:
75:
70:
33:
30:
13:
10:
9:
6:
4:
3:
2:
2089:
2078:
2075:
2073:
2070:
2068:
2065:
2064:
2062:
2038:
2032:
2029:
2024:
2018:
2015:
2002:
1998:
1991:
1988:
1976:
1972:
1965:
1962:
1957:
1951:
1935:
1931:
1924:
1921:
1918:
1914:
1911:
1906:
1903:
1890:
1884:
1881:
1876:
1869:
1866:
1862:
1858:
1852:
1848:
1843:
1842:
1833:
1830:
1817:
1813:
1807:
1804:
1801:
1797:
1794:
1788:
1785:
1780:
1776:
1772:
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1762:
1754:
1747:
1746:
1738:
1735:
1720:
1713:
1710:
1698:
1692:
1689:
1678:. pcguide.com
1677:
1670:
1667:
1656:
1652:
1645:
1642:
1631:
1627:
1620:
1617:
1605:
1601:
1597:
1591:
1588:
1585:
1580:
1577:
1566:on 2013-03-14
1565:
1561:
1554:
1551:
1540:on 2013-03-14
1539:
1535:
1528:
1526:
1522:
1511:on 2012-03-20
1510:
1506:
1499:
1496:
1485:on 2012-01-08
1484:
1480:
1479:"Settle Time"
1473:
1470:
1459:on 2012-04-19
1458:
1454:
1447:
1444:
1433:on 2010-11-29
1432:
1428:
1422:
1419:
1407:
1401:
1398:
1386:
1379:
1376:
1372:
1366:
1363:
1359:
1353:
1350:
1339:on 2012-03-24
1335:
1328:
1322:
1319:
1308:on 2012-01-01
1307:
1303:
1296:
1293:
1288:
1282:
1278:
1277:
1269:
1266:
1254:
1247:
1244:
1239:
1235:
1229:
1226:
1213:
1206:
1200:
1198:
1194:
1183:on 2011-01-05
1182:
1178:
1174:
1168:
1165:
1153:
1152:anandtech.com
1149:
1142:
1139:
1127:
1123:
1117:
1114:
1101:
1097:
1091:
1088:
1076:
1072:
1066:
1063:
1052:on 2010-12-17
1048:
1041:
1035:
1032:
1017:
1010:
1007:
994:
987:
984:
973:on 2012-04-19
972:
968:
961:
959:
957:
953:
948:
944:
938:
935:
924:on 2011-07-15
923:
919:
913:
911:
909:
907:
905:
903:
901:
897:
885:
879:
876:
865:on 2012-03-19
864:
860:
859:"Access Time"
853:
851:
847:
835:
829:
827:
825:
821:
809:
803:
800:
794:
790:
787:
785:
782:
780:
777:
775:
772:
771:
767:
765:
763:
759:
754:
749:
746:
744:
740:
735:
727:
725:
723:
712:
709:November 2020
703:
699:
696:This section
694:
691:
687:
686:
680:
678:
676:
672:
664:
662:
655:
651:
648:
644:
640:
636:
633:
632:
631:
627:
624:
623:failure rates
620:
615:
608:
606:
603:
599:
588:
581:
574:
572:
570:
569:
568:Areal density
559:
557:
554:
550:
542:
540:
537:
530:
526:
522:
518:
515:
511:
508:
504:
503:
502:
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366:
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344:
339:
333:
330:
329:
325:
323:
320:
319:
315:
314:
313:
311:
307:
303:
299:
295:
294:spindle motor
291:
287:
283:
279:
275:
266:
263:
258:
255:
250:
247:
242:
239:
234:
231:
222:
217:
216:
207:
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202:
197:
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191:
187:
183:
179:
171:
169:
167:
162:
155:
153:
151:
147:
142:
140:
135:
133:
129:
128:stepper motor
121:
119:
116:
111:
109:
105:
101:
96:
88:
84:
81:
79:
76:
74:
71:
69:
66:
65:
64:
61:
59:
55:
54:transfer data
51:
50:response time
47:
38:
31:
29:
27:
23:
19:
2044:. Retrieved
2031:
2017:
2005:. Retrieved
2001:the original
1990:
1978:. Retrieved
1974:
1964:
1938:. Retrieved
1934:ServeTheHome
1933:
1923:
1905:
1893:. Retrieved
1883:
1868:
1860:
1840:
1832:
1820:. Retrieved
1816:the original
1806:
1787:
1779:the original
1774:
1764:
1744:
1737:
1726:. Retrieved
1712:
1701:. Retrieved
1691:
1680:. Retrieved
1669:
1658:. Retrieved
1654:
1644:
1633:. Retrieved
1629:
1619:
1608:. Retrieved
1604:the original
1590:
1579:
1568:. Retrieved
1564:the original
1553:
1542:. Retrieved
1538:the original
1513:. Retrieved
1509:the original
1498:
1487:. Retrieved
1483:the original
1472:
1461:. Retrieved
1457:the original
1446:
1435:. Retrieved
1431:the original
1421:
1410:. Retrieved
1400:
1389:. Retrieved
1378:
1365:
1352:
1341:. Retrieved
1334:the original
1321:
1310:. Retrieved
1306:the original
1295:
1275:
1268:
1257:. Retrieved
1246:
1237:
1228:
1216:. Retrieved
1185:. Retrieved
1181:the original
1167:
1157:December 19,
1155:. Retrieved
1151:
1141:
1130:. Retrieved
1126:the original
1116:
1104:. Retrieved
1100:the original
1090:
1079:. Retrieved
1075:the original
1065:
1054:. Retrieved
1047:the original
1034:
1023:. Retrieved
1009:
997:. Retrieved
986:
975:. Retrieved
971:the original
946:
937:
926:. Retrieved
922:the original
888:. Retrieved
886:. 2011-04-25
878:
867:. Retrieved
863:the original
838:. Retrieved
836:. redhat.com
812:. Retrieved
802:
779:Hybrid drive
750:
747:
737:
719:
706:
702:adding to it
697:
668:
659:
639:Parallel ATA
628:
612:
604:
600:
596:
566:
563:
546:
538:
534:
500:
467:
463:
459:
455:
453:
435:
431:
423:
421:
412:
404:
402:
393:green drives
392:
370:
361:
346:
336:
331:
327:
326:
321:
317:
316:
305:
301:
281:
277:
273:
272:
198:
176:Measured in
175:
160:
159:
149:
145:
143:
136:
125:
114:
112:
94:
92:
62:
49:
45:
43:
15:
1980:15 February
1793:Intelliseek
1371:interleaved
1106:October 19,
967:"Seek Time"
641:(PATA) and
426:settle time
290:disk sector
218:HDD spindle
150:full stroke
108:device type
83:Settle time
46:access time
32:Access time
22:access time
2061:Categories
1940:6 November
1728:2014-05-23
1703:2014-05-31
1682:2012-04-04
1660:2011-07-03
1635:2011-07-03
1610:2013-12-02
1570:2012-04-04
1544:2012-04-04
1515:2012-04-04
1489:2012-04-04
1463:2012-04-04
1437:2011-07-06
1412:2011-07-06
1391:2011-07-03
1343:2011-07-06
1312:2012-04-04
1259:2011-07-05
1187:2011-01-15
1132:2011-07-04
1081:2011-07-04
1056:2011-07-06
1025:2011-08-02
999:January 7,
977:2012-04-04
928:2011-07-14
890:2011-07-03
869:2012-04-04
840:2011-07-01
814:2011-07-01
795:References
681:SMR drives
643:Serial ATA
575:Interleave
475:Media rate
460:throughput
381:waste heat
225:rotational
132:voice coil
100:concentric
1724:. Seagate
591:IBM PC XT
436:off track
389:spun down
227:latency
95:seek time
89:Seek time
68:Seek time
1950:cite web
1913:Archived
1895:26 April
1822:26 April
1796:Archived
768:See also
322:= 60/rpm
286:rotation
280:or just
2046:July 6,
2007:July 1,
1655:PCWorld
1630:ITWorld
1600:Seagate
1218:July 6,
377:spin-up
310:spin-up
282:latency
223:Average
201:Seagate
2042:. 2010
1853:
1283:
525:1x CDs
521:buffer
514:buffer
507:buffer
432:settle
264:15,000
256:10,000
220:speed
104:spiral
2040:(PDF)
1756:(PDF)
1749:(PDF)
1722:(PDF)
1408:. IBM
1337:(PDF)
1330:(PDF)
1208:(PDF)
1050:(PDF)
1043:(PDF)
1019:(PDF)
637:Some
399:Other
267:2.00
259:3.00
251:4.17
248:7,200
243:5.56
240:5,400
235:7.14
232:4,200
58:heads
2048:2011
2009:2011
1982:2022
1956:link
1942:2020
1897:2012
1851:ISBN
1824:2012
1358:drum
1281:ISBN
1220:2011
1159:2013
1108:2012
1001:2020
784:IOPS
774:vRPM
758:TRIM
454:The
422:The
403:The
182:DVRs
166:IOPS
148:and
44:The
24:and
704:.
585:10
466:or
411:or
194:AAM
178:dBA
102:or
48:or
2063::
1973:.
1952:}}
1948:{{
1932:.
1859:.
1849:.
1847:62
1773:.
1751:.
1653:.
1628:.
1598:.
1524:^
1236:.
1212:HP
1210:.
1196:^
1175:.
1150:.
955:^
945:.
899:^
849:^
823:^
587:MB
417:ÎĽs
139:ms
28:.
2050:.
2025:.
2011:.
1984:.
1958:)
1944:.
1899:.
1877:.
1826:.
1731:.
1706:.
1685:.
1663:.
1638:.
1613:.
1573:.
1547:.
1518:.
1492:.
1466:.
1440:.
1415:.
1394:.
1346:.
1315:.
1289:.
1262:.
1222:.
1190:.
1161:.
1135:.
1110:.
1084:.
1059:.
1028:.
1003:.
980:.
949:.
931:.
893:.
872:.
843:.
817:.
711:)
707:(
675:g
98:(
Text is available under the Creative Commons Attribution-ShareAlike License. Additional terms may apply.
