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![]() | Text and/or other creative content from this version of Rotational delay was copied or moved into Disk drive performance characteristics#Rotational latency with this edit. The former page's history now serves to provide attribution for that content in the latter page, and it must not be deleted as long as the latter page exists. |
Proposed we keep the overall power consumption section in HDD article. I pulled out the key elements and included them in the article, but so much of this is great data on power which I believe should stay with the HDD article. At this time I have not removed it from the HDD article.
Heat dissipation is tied directly to power consumption, and as drives age, disk [[failure rate]]s increase at higher drive temperatures.<ref name="xbit-2007-12-06">{{cite news |newspaper=Xbit Laboratories |title=Hard Disk Drive Power Consumption Measurements: X-bit’s Methodology |date=6 December 2007 |first=Oleg |last=Artamonov |url=http://www.xbitlabs.com/articles/storage/display/hdd-power-cons.html |accessdate=2011-07-03}}</ref> 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 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).<ref>e.g. Western Digital's [http://www.wdc.com/en/flash/index.asp?family=intelliseek Intelliseek]</ref> 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,<ref>[http://www.xbitlabs.com/news/storage/display/20071022123416.html Hitachi Unveils Energy-Efficient Hard Drive with Variable Spindle Speed.]</ref> and disabling internal components when not in use.<ref>{{cite book |title=Green tech: how to plan and implement sustainable IT solutions |first=Lawrence |last=Webber |first2=Michael |last2=Wallace |isbn=081441446X |year=2009 |url=http://books.google.com/books?id=BKTALNq5ceAC&lpg=PA62&dq=green%20disk%20drive&pg=PA62#v=onepage&q=green%20disk%20drive&f=false |page=62 |accessdate=2011-07-03}}</ref>
Also in systems where there might be multiple hard disk drives, there are various ways of controlling when the hard drives spin up since the highest current is drawn at that time.
*On SCSI hard disk drives, the SCSI controller can directly control spin up and spin down of the drives.
*On [[Parallel ATA]] (aka PATA) and [[Serial ATA]] (SATA) hard disk drives, some support [[power-up in standby]] or PUIS. The hard disk drive will not spin up until the controller or system BIOS issues a specific command to do so. This limits the power draw or consumption upon power on.
*Some SATA II hard disk drives support staggered spin-up, allowing the computer to spin up the drives in sequence to reduce load on the power supply when booting.<ref>{{cite news |title=Hitachi Deskstar 7K500 500GB HDD: As fast as it's big? |author=Trusted Reviews |date=31 August 2005 |http://www.theregister.co.uk/2005/08/31/review_hitachi_7k500/ |accessdate=2011-07-03}}</ref>
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, may take as long as several seconds.<ref>[http://www.almaden.ibm.com/almaden/mobile_hard_drives.html#2 Adaptive Power Management for Mobile Hard Drives]</ref>
====Shock resistance====
Shock resistance is especially important for mobile devices. Some laptops now include [[active hard drive protection]] 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 [[Gravitational acceleration|g]] for operating and 1000 g for non-operating.<ref>[http://www.seagate.com/ww/v/index.jsp?vgnextoid=5fb658a3fd20a110VgnVCM100000f5ee0a0aRCRD Momentus 5400.5 SATA 3Gb/s 320-GB Hard Drive]</ref>
§ Music Sorter § ( talk) 07:33, 5 July 2011 (UTC)
[[Image:IBM PC XT 10 meg MFM low level format.jpg|thumb|200px|A low-level formatting tool running tests to find the highest performance interleave choice for a 10-megabyte IBM PC XT hard drive.]] Sector interleave is a mostly obsolete device characteristic related to access time, 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 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.
However, because interleaving introduces intentional physical delays into the drive mechanism, 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 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.
Modern technology is capable of reading data as fast as it can be obtained from the spinning platters, so hard drives usually have a fixed sector interleave ratio of 1:1, which is effectively no interleaving being used.
Access time is common to all data storage and the disk specific issues are all ready well covered in this article and/or its parent. Arguably it applies to data communications also (at least latency and data rate do), although I don't recall the term being used too much in that art. So there is nothing to merge here. Rather the Access Time article needs a lot of work to broaden it or we might merge it into Computer data storage. Tom94022 ( talk) 15:28, 9 July 2011 (UTC)
Note: the following was placed on the talk:Access time page and I copied it here for simplicity of seeing all the feedback. § Music Sorter § ( talk) 15:16, 12 July 2011 (UTC)
Agree Merge the disk-related section to Disk drive performance characteristics, simply because there it would contribute to an interesting article whereas here it can say nothing beyond a simple, unhelpful definition. -- Kubanczyk ( talk) 09:10, 12 July 2011 (UTC)
All of the content in the current stub Seek time article has been included in this article. I propose we change this page to a redirect to Disk drive performance characteristics#Seek time. § Music Sorter § ( talk) 05:33, 10 July 2011 (UTC)
All of the content in the current stub Rotational delay article has been included in this article. I propose we change this page to a redirect to Disk drive performance characteristics#Rotational delay. § Music Sorter § ( talk) 07:43, 10 July 2011 (UTC)
The result of the move request was: No consensus to move. Sounds like the scope needs to be hammered out first. Cúchullain t/ c 14:33, 30 November 2012 (UTC)
Hard disk drive performance characteristics → Disk drive performance characteristics – The recent addition of "hard" to the title, because "this is exclusively about HDDs", is not supported by the article text. Solid-state, optical and floppy disks are also part of the scope of the article. Relisted. Jenks24 ( talk) 06:28, 4 November 2012 (UTC) Wbm1058 ( talk) 17:50, 18 October 2012 (UTC)
None of these links are specific, i.e., Hard disk access time, hard disk seek time, hard disk rotational latency. Are these characteristics limited to hard disk drives, or can other types of disk drives be measured by these characteristics? If so, do we need a separate link for floppy disk seek time, for example? – Wbm1058 ( talk) 21:37, 13 November 2012 (UTC)
In the http://en.wikipedia.org/wiki/Hard_disk_drive_performance_characteristics#Data_transfer_rate, the terms "disk-to-buffer" and "buffer-to-computer" are introduced in the examples of throughputs. They are not discussed in the preamble or the definitions in this sections, and thus make the examples harder to understand. We could probably just put a: `aka "buffer-to-computer" ` in the preamble, where the different factors are described. — Preceding unsigned comment added by Myok ( talk • contribs) 00:00, 31 December 2012 (UTC)
This article does a good job of explaining what causes access times and data transfer rates. However, it does not indicate their relative importance. How much attention should one pay to transfer rate, versus the attention paid to access time? The answer depends on the workload considered. We could give a general answer based on studies, saying for example that server HDDs spend a third of their active time seeking and 2 thirds transferring, based on an average of many HDDs. Or, explain how to measure how a certain HDD's activity. -- Chealer ( talk) 16:26, 16 November 2013 (UTC)
I have corrected several cases where the principle of the section title was violated.
Please pay attention the next time around! 80.226.24.8 ( talk) 20:49, 4 June 2015 (UTC)
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Would like to know some data transfer rates lowest to highest of SMR drives.
From HDD1 -->> to HDD2. And from HDD1 -->> to HDD1.
![]() | This article is rated Start-class on Wikipedia's
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![]() | Text and/or other creative content from this version of Rotational delay was copied or moved into Disk drive performance characteristics#Rotational latency with this edit. The former page's history now serves to provide attribution for that content in the latter page, and it must not be deleted as long as the latter page exists. |
Proposed we keep the overall power consumption section in HDD article. I pulled out the key elements and included them in the article, but so much of this is great data on power which I believe should stay with the HDD article. At this time I have not removed it from the HDD article.
Heat dissipation is tied directly to power consumption, and as drives age, disk [[failure rate]]s increase at higher drive temperatures.<ref name="xbit-2007-12-06">{{cite news |newspaper=Xbit Laboratories |title=Hard Disk Drive Power Consumption Measurements: X-bit’s Methodology |date=6 December 2007 |first=Oleg |last=Artamonov |url=http://www.xbitlabs.com/articles/storage/display/hdd-power-cons.html |accessdate=2011-07-03}}</ref> 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 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).<ref>e.g. Western Digital's [http://www.wdc.com/en/flash/index.asp?family=intelliseek Intelliseek]</ref> 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,<ref>[http://www.xbitlabs.com/news/storage/display/20071022123416.html Hitachi Unveils Energy-Efficient Hard Drive with Variable Spindle Speed.]</ref> and disabling internal components when not in use.<ref>{{cite book |title=Green tech: how to plan and implement sustainable IT solutions |first=Lawrence |last=Webber |first2=Michael |last2=Wallace |isbn=081441446X |year=2009 |url=http://books.google.com/books?id=BKTALNq5ceAC&lpg=PA62&dq=green%20disk%20drive&pg=PA62#v=onepage&q=green%20disk%20drive&f=false |page=62 |accessdate=2011-07-03}}</ref>
Also in systems where there might be multiple hard disk drives, there are various ways of controlling when the hard drives spin up since the highest current is drawn at that time.
*On SCSI hard disk drives, the SCSI controller can directly control spin up and spin down of the drives.
*On [[Parallel ATA]] (aka PATA) and [[Serial ATA]] (SATA) hard disk drives, some support [[power-up in standby]] or PUIS. The hard disk drive will not spin up until the controller or system BIOS issues a specific command to do so. This limits the power draw or consumption upon power on.
*Some SATA II hard disk drives support staggered spin-up, allowing the computer to spin up the drives in sequence to reduce load on the power supply when booting.<ref>{{cite news |title=Hitachi Deskstar 7K500 500GB HDD: As fast as it's big? |author=Trusted Reviews |date=31 August 2005 |http://www.theregister.co.uk/2005/08/31/review_hitachi_7k500/ |accessdate=2011-07-03}}</ref>
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, may take as long as several seconds.<ref>[http://www.almaden.ibm.com/almaden/mobile_hard_drives.html#2 Adaptive Power Management for Mobile Hard Drives]</ref>
====Shock resistance====
Shock resistance is especially important for mobile devices. Some laptops now include [[active hard drive protection]] 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 [[Gravitational acceleration|g]] for operating and 1000 g for non-operating.<ref>[http://www.seagate.com/ww/v/index.jsp?vgnextoid=5fb658a3fd20a110VgnVCM100000f5ee0a0aRCRD Momentus 5400.5 SATA 3Gb/s 320-GB Hard Drive]</ref>
§ Music Sorter § ( talk) 07:33, 5 July 2011 (UTC)
[[Image:IBM PC XT 10 meg MFM low level format.jpg|thumb|200px|A low-level formatting tool running tests to find the highest performance interleave choice for a 10-megabyte IBM PC XT hard drive.]] Sector interleave is a mostly obsolete device characteristic related to access time, 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 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.
However, because interleaving introduces intentional physical delays into the drive mechanism, 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 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.
Modern technology is capable of reading data as fast as it can be obtained from the spinning platters, so hard drives usually have a fixed sector interleave ratio of 1:1, which is effectively no interleaving being used.
Access time is common to all data storage and the disk specific issues are all ready well covered in this article and/or its parent. Arguably it applies to data communications also (at least latency and data rate do), although I don't recall the term being used too much in that art. So there is nothing to merge here. Rather the Access Time article needs a lot of work to broaden it or we might merge it into Computer data storage. Tom94022 ( talk) 15:28, 9 July 2011 (UTC)
Note: the following was placed on the talk:Access time page and I copied it here for simplicity of seeing all the feedback. § Music Sorter § ( talk) 15:16, 12 July 2011 (UTC)
Agree Merge the disk-related section to Disk drive performance characteristics, simply because there it would contribute to an interesting article whereas here it can say nothing beyond a simple, unhelpful definition. -- Kubanczyk ( talk) 09:10, 12 July 2011 (UTC)
All of the content in the current stub Seek time article has been included in this article. I propose we change this page to a redirect to Disk drive performance characteristics#Seek time. § Music Sorter § ( talk) 05:33, 10 July 2011 (UTC)
All of the content in the current stub Rotational delay article has been included in this article. I propose we change this page to a redirect to Disk drive performance characteristics#Rotational delay. § Music Sorter § ( talk) 07:43, 10 July 2011 (UTC)
The result of the move request was: No consensus to move. Sounds like the scope needs to be hammered out first. Cúchullain t/ c 14:33, 30 November 2012 (UTC)
Hard disk drive performance characteristics → Disk drive performance characteristics – The recent addition of "hard" to the title, because "this is exclusively about HDDs", is not supported by the article text. Solid-state, optical and floppy disks are also part of the scope of the article. Relisted. Jenks24 ( talk) 06:28, 4 November 2012 (UTC) Wbm1058 ( talk) 17:50, 18 October 2012 (UTC)
None of these links are specific, i.e., Hard disk access time, hard disk seek time, hard disk rotational latency. Are these characteristics limited to hard disk drives, or can other types of disk drives be measured by these characteristics? If so, do we need a separate link for floppy disk seek time, for example? – Wbm1058 ( talk) 21:37, 13 November 2012 (UTC)
In the http://en.wikipedia.org/wiki/Hard_disk_drive_performance_characteristics#Data_transfer_rate, the terms "disk-to-buffer" and "buffer-to-computer" are introduced in the examples of throughputs. They are not discussed in the preamble or the definitions in this sections, and thus make the examples harder to understand. We could probably just put a: `aka "buffer-to-computer" ` in the preamble, where the different factors are described. — Preceding unsigned comment added by Myok ( talk • contribs) 00:00, 31 December 2012 (UTC)
This article does a good job of explaining what causes access times and data transfer rates. However, it does not indicate their relative importance. How much attention should one pay to transfer rate, versus the attention paid to access time? The answer depends on the workload considered. We could give a general answer based on studies, saying for example that server HDDs spend a third of their active time seeking and 2 thirds transferring, based on an average of many HDDs. Or, explain how to measure how a certain HDD's activity. -- Chealer ( talk) 16:26, 16 November 2013 (UTC)
I have corrected several cases where the principle of the section title was violated.
Please pay attention the next time around! 80.226.24.8 ( talk) 20:49, 4 June 2015 (UTC)
Hello fellow Wikipedians,
I have just modified 8 external links on Hard disk drive performance characteristics. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.
This message was posted before February 2018.
After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than
regular verification using the archive tool instructions below. Editors
have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the
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(last update: 5 June 2024).
Cheers.— InternetArchiveBot ( Report bug) 03:52, 30 October 2017 (UTC)
Would like to know some data transfer rates lowest to highest of SMR drives.
From HDD1 -->> to HDD2. And from HDD1 -->> to HDD1.