机械硬盘---讨论

easylife

Key Technological Firsts

0 X- ]/ i8 @% X2 v) ]There have been a number of important "firsts" in the world of hard disks over their first 40 or so years. The following is a list, in chronological order, of some of the products developed during the past half-century that introduced key or important technologies in the PC world. Note the dominance of IBM in the list; in this author's opinion Big Blue does not get nearly as much credit as it deserves for being the main innovator in the storage world. Note also how many years it took for many of these technologies to make it to the PC world (sometimes as much as a decade, due to the initial high cost of most new technologies). I
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First Hard Disk (1956): IBM's RAMAC is introduced. It has a capacity of about 5 MB, stored on 50 24" disks. Its areal density is a mere 2,000 bits per square inch and its data throughput 8,800 bits/s.
& U1 [% q% t9 R4 ]0 H( EFirst Air Bearing Heads (1962): IBM's model 1301 lowers the flying height of the heads to 250 microinches. It has a 28 MB capacity on half as many heads as the original RAMAC, and increases both areal density and throughput by about 1000%.
6 ?* _. g* c: Q8 y1 P$ n' zFirst Removable Disk Drive (1965): IBM's model 2310 is the first disk drive with a removable disk pack. While many PC users think of removable hard disks as being a modern invention, in fact they were very popular in the 1960s and 1970s.
First Ferrite Heads (1966): IBM's model 2314 is the first hard disk to use ferrite core heads, the first type later used on PC hard disks.
: M' v+ V7 n' W" y2 p5 X( R+ g4 jFirst Modern Hard Disk Design (1973): IBM's model 3340, nicknamed the "Winchester", is introduced. With a capacity of 60 MB it introduces several key technologies that lead to it being considered by many the ancestor of the modern disk drive.
* f5 f& t& H2 c& K6 rFirst Thin Film Heads (1979): IBM's model 3370 is the first with thin film heads, which would for many years be the standard in the PC industry.
( ~- K- A. N" e) |3 J2 WFirst Eight-Inch Form Factor Disk (1979): IBM's model 3310 is the first disk drive with 8" platters, greatly reduced in size from the 14" that had been the standard for over a decade.
  ?- B. F- C3 K( LFirst 5.25" Form Factor Disk (1980): Seagate's ST-506 is the first drive in the 5.25" form factor, used in the earliest PCs.
First 3.5" Form Factor Disk Drive (1983): Rodime introduces the RO352, the first disk drive to use the 3.5" form factor, which became one of the most important industry standards.
7 ~" s4 m6 l. L! z2 _( MFirst Expansion Card Disk Drive (1985): Quantum introduces the Hardcard, a 10.5 MB hard disk mounted on an ISA expansion card for PCs that were originally built without a hard disk. This product put Quantum "on the map" so to speak.
First Voice Coil Actuator 3.5" Drive (1986): Conner Peripherals introduces the CP340, the first disk drive to use a voice coil actuator.
First "Low-Profile" 3.5" Disk Drive (1988): Conner Peripherals introduces the CP3022, which was the first 3.5" drive to use the reduced 1" height now called "low profile" and the standard for modern 3.5" drives.
  h7 ^2 Z$ Y+ |6 g0 B5 ?0 YFirst 2.5" Form Factor Disk Drive (1988): PrairieTek introduces a drive using 2.5" platters. This size would later become a standard for portable computing.
First Drive to use Magnetoresistive Heads and PRML Data Decoding (1990): IBM's model 681 (Redwing), an 857 MB drive, is the first to use MR heads and PRML.
. r6 `  M; H' ]1 LFirst Thin Film Disks (1991): IBM's "Pacifica" mainframe drive is the first to replace oxide media with thin film media on the platter surface.
First 1.8" Form Factor Disk Drive (1991): Integral Peripherals' 1820 is the first hard disk with 1.8" platters, later used for PC-Card disk drives.
First 1.3" Form Factor Disk Drive (1992): Hewlett Packard's C3013A is the first 1.3" drive.
9 h1 F, U9 j, ?; O- [3 XThe source for much of this information is DISK/TREND Inc. In the 1990s, technological advances in every aspect of hard disks began coming at a fast and furious pace; it would take too long to research and list them all, so I am stopping at 1992.

easylife

关键的"技术第一":

在硬盘界过去的40多年里产生了许多重要的“第一”，接下来的是一个按时间先后顺序的列表,列举出了在过去近半个世纪个人电脑世界里一些产品开发关键技术。请留意IBM在列表中醒目的主导地位，根据作者的观点，蓝色巨人并没有得到与其在存储业界所做贡献相称的认可。同时也请注意她花了多少年时间才使硬盘进入个人电脑（有时候多达10年之久，都归于大部分新技术高昂的初期成本）。

第一个硬盘（1956）： 发明IBM的RAMAC。 容量5MB，存储在50张25英寸的盘片上。它的面密度仅仅只有大概2，000字节每平方英寸，而且它的数据传输速度是8，800字节每秒。
' J" f8 T) ^- r# p0 x第一个空气轴承磁头（1962）：IBM的1301将飞行高度降低到250微英寸，它拥有28MB容量，磁头数目只有初期RAMAC磁头数目的一半，并且将磁面密度提高了一倍，数据速度提高10倍。
# G% e7 P+ {8 z) D第一个可移动硬盘（1966）：IBM的2310是第一个具有可可移动封装的硬盘。而大多数电脑使用者认为可移动硬盘是现代的发明，实际上在20世纪60和70年代之间是非常流行的。
第一个铁氧体磁头（1979）：IBM的2314是第一个使用铁氧体磁心磁头的硬盘，这种磁头是第一种使用在个人电脑硬盘中的磁头。
- }' h) D; J8 v7 O) V第一个现代硬盘设计（1973）： IBM推出3340，别名“温彻斯特” ，60MB容量，它引进一些关键的硬盘技术，被后来许多的现代硬盘的雏形所参考和引用。
1 ?! \! w/ D% q5 x第一个薄膜磁头（1979）： IBM的3370首先采用了薄膜磁头，之后多年一直是个人电脑硬盘的标准。
第一个8英寸硬盘（1979）： IBM的3310是第一个配备8英寸盘片的硬盘，它将硬盘的尺寸从14英寸有效地减小到了8英寸，并一度保持了业界标准尺寸达10之久。


/ O  R4 j7 m9 g9 M# ^. X0 y第一个5.25英寸硬盘（1980）：Seagate 的ST-506是第一个5.25英寸硬盘，使用在最早期的个人电脑上。
第一个3.5英寸硬盘 （1983）：Rodime推出了RO352，第一个3.5英寸硬盘，成为最重要的行业标准尺寸之一。
- o, F- P; S' I& p! M6 c第一个扩展卡式硬盘（1985）： Quantum推出了Hardcard，一个安装在本来没有硬盘的个人电脑里，固定在一张ISA扩展卡上的10.5MB的硬盘。这个产品使Quantum在储存界获得了好名声。
* ?1 N% k4 w: }0 V, D3 l第一个（使用）音圈制动臂的硬盘（1986）： Conner Peripherals推出了CP340, 第一个使用音圈制动臂的硬盘。
第一个“低矮外形”的3.5硬盘（1988）：Conner Peripherals推出CP3022，它是第一个将3.5英寸硬盘高度降低到1英寸的硬盘，被称为“低矮外形”硬盘，并成为现代3.5硬盘的标准。
第一个2.5英寸硬盘（1988）：PrairieTek推出了使用2.5盘片的硬盘，这个尺寸后来成为笔记本电脑的标准。
第一个使用磁阻磁头和PRML解码的硬盘（1990）： IBM的681（红翼鸫），容量857MB，是第一个使用磁阻式磁头和PRML的硬盘。
第一个薄膜碟片（1991）：IBM的“Pacifica”架构硬盘是第一个取代氧化物碟片的驱动器，其盘片涂敷的是薄膜磁性物质。
3 C& r: U0 G% r7 J5 n- W第一个1.5英寸硬盘（1991）： Integral Peripherals的1820是第一个1.8英寸硬盘，后来作为电脑卡式硬盘使用。
4 p  P2 `$ `0 p) f& Q8 P第一个1.3英寸硬盘（1992）：Hewlett Packard的C3013A是第一个1.3硬盘。

easylife

Hard Disk Trends

' m' w% W1 R+ b8 EThe most amazing thing about hard disks is that they both change and don't change more than most other components. In terms of their basic design, today's hard disks aren't a lot different than the 10 MB clunkers installed in the first IBM PC/XTs in the early 1980s. However, in terms of their capacity, storage, reliability and other characteristics, hard drives have probably improved more than any other PC component. Let's take a look at some of the trends in various important hard disk characteristics:

7 M; g* k/ m- B" [0 i3 J Areal Density: The areal density of hard disk platters continues to increase at an amazing rate even exceeding some of the optimistic predictions of a few years ago. Densities in the lab are now exceeding 35 Gbits/in2, and modern disks are now packing as much as 20 GB of data onto a single 3.5" platter!

& D8 f& _  n+ o3 w) v& MCapacity: Hard disk capacity continues to not only increase, but increase at an accelerating rate. From 10 MB in 1981, we are now well over 10 GB in 2000 and will probably hit 100 GB within a year for consumer drives.

  X/ r7 y* c* ~" a! O, p* ASpindle Speed: The move to faster and faster spindle speeds continues. Since increasing the spindle speed improves both random-access and sequential performance, this is likely to continue. Once the domain of high-end SCSI drives, 7200 RPM spindles are now standard on mainstream IDE/ATA drives. A 15,000 RPM SCSI drive was announced by Seagate in early 2000.

Form Factor: The trend in form factors is downward: to smaller and smaller drives. 5.25" drives have now all but disappeared from the mainstream PC market, with 3.5" drives dominating the desktop and server segment. In the mobile world, 2.5" drives are the standard with smaller sizes becoming more prevalent; IBM in 1999 announced its Microdrive which is a tiny 170 MB or 340 MB device only an inch in diameter and less than 0.25" thick! Over the next few years, desktop and server drives are likely to transition to the 2.5" form factor as well. The primary reasons for this "shrinking trend" include the enhanced rigidity of smaller platters, reduction of mass to enable faster spin speeds, and improved reliability due to enhanced ease of manufacturing.
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Performance: Both positioning and transfer performance factors are improving. The speed with which data can be pulled from the disk is increasing more rapidly than positioning performance is improving, suggesting that over the next few years addressing seek time and latency will be the areas of greatest value to hard disk engineers.
, Z' |7 i/ `$ k0 m/ r; \8 N; A$ cReliability: The reliability of hard disks is improving slowly as manufacturers refine their processes and add new reliability-enhancing features, but this characteristic is not changing nearly as rapidly as the others above. One reason is that the technology is constantly changing, and the performance envelope constantly being pushed; it's much harder to improve the reliability of a product when it is changing rapidly.
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0 }$ ?2 r0 E; A7 T  v3 T5 lRAID: Once the province of only high-end servers, the use of multiple disk arrays to improve performance and reliability is becoming increasingly common, and is now even seen in consumer desktop machines. Over the next few years I predict that RAID will become the "next big thing" as the thirst for performance increases, and in five years we may see new PCs commonly shipping with multiple hard disks configured as an array.
2 F3 D# Y, O9 y) T  V$ k, F  iInterfaces: Despite the introduction to the PC world of new interfaces such as IEEE-1394 and USB (universal serial bus) the mainstream interfaces in the PC world are the same as they were through the 1990s: IDE/ATA and SCSI. The interfaces themselves continue to create new and improved standards with higher maximum transfer rates, to match the increase in performance of the hard disks themselves.
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[ 本帖最后由 easylife 于 2008-11-23 23:29 编辑 ]

龙游大海

结构原理上来说硬盘是一个简单的机械产品.有硬盘结构图吗？发一个上来

easylife

原帖由 龙游大海 于 2008-12-7 09:48 发表
结构原理上来说硬盘是一个简单的机械产品.有硬盘结构图吗？发一个上来

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# t) Y* H+ D  N; W我想这样描述更合适, "从外观形式来说,硬盘似乎是一个简单的机械产品.".
/ w. {/ P# e  _8 {. _----个人认为机械硬盘是20世纪工程界一个伟大的发明, 高度集成的机电产品.融合了磁记录,wafer制造和切割(磁头),精密机械设计(包括大量振动问题,液体动压轴承,电磁分析),精密servo控制,pcb设计, firmwave.

8 |+ P$ K; |# `# J& {! Q举个例子, 机械部分压紧碟片的零件(clamp)设计,要求其能压紧碟片,保证硬盘在承受水平方向1000G左右的冲击时碟片不发生移动,或竖直方向1000G冲击(跌落)时碟片不能碰到其他零件,这样就要求clamp安装压紧后的紧固力足够大.
- |( r/ D" w% j* u/ _9 B5 }但是, 我们希望碟片被clamp压紧后变形(flatness)尽可能小,一般在几个微米左右.这样就要求clamp紧固后压紧力也不能太大, 否则导致硬盘工作时磁头工况恶劣,甚至不能正常工作.
  U  f# s& |  ]7 D6 M  e6 V7 G综上所叙,clamping force是在一定范围内的,至于nominal value,tolerance,需要计算,仿真,考虑加工工艺和关键尺寸CPK情况.
3 d: \% H) G; L2 j1 V毫不夸张的说,一个零件设计足够做一个博士课题
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. K9 a/ U3 ?& {& k[ 本帖最后由 easylife 于 2008-12-16 23:59 编辑 ]

easylife

整理了一份关于其历史的文档, 资料来自于以下连接
3 q6 |3 m$ G* f$ [; G; n  ?http://www.pcshow.net/detail-36-427685-2.html
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祝大家新年快乐!

easylife

某大学收藏的硬盘, 很难想象以前的硬盘能重大几百公斤甚至数吨

长弓宏

世界几大硬盘企业都在中国有全工艺流程的工厂

+ A# a7 R1 g8 E- F4 d东莞的新科(SAE TDK的子公司)
深圳的日立
苏州的希捷
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( Z4 `9 S: X+ _  q都有高等级的无尘室
更不用说那些IC制造商比如和舰 中芯 海力士
$ T  r+ I0 h" s, a- ]- j无尘室系统全是国外造的  但是是能进口到中国的
无尘室的桌子 凳子 笔 推车 人穿的衣服等等任何东西都要接地防静电 每天都要做尘粒测试和静电测试

easylife

原帖由 长弓宏 于 2009-1-6 20:05 发表
世界几大硬盘企业都在中国有全工艺流程的工厂

: l, V9 n' o. E8 e  B东莞的新科(SAE TDK的子公司)
* H% ]1 V8 k8 a6 J1 Q深圳的日立
苏州的希捷
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4 u4 |: c( K" b* Z* N" a. ?0 a都有高等级的无尘室
. N2 L# z: a3 F1 ~7 ~( i+ Y" T更不用说那些IC制造商比如和舰 中芯 海力士
+ X0 N) G5 C% v! n" r无尘室系统全是国外造的  但是是能进口到 ...

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. r* Y2 B  H2 _! ]朋友了解得还不少
7 @0 g6 j; `5 P6 v5 u9 |不过我没有见过出于防静电需要的笔还需要接地的，一般书写的笔采用特制的耗散性材料---半导体，不易产生静电，导电也较快。

, w9 D  s% Y& N听说一套无尘室使用的内六角扳手需要1万多美元（没有证实过）。。

紫木棉

机械磁盘在最近十几年的发展，可以说是突飞猛进。但就是这样的发展，磁盘也没有把磁带机扫入历史的垃圾堆里，直到现在，磁带机依旧在不少地方发挥作用。所以个人觉得，即使将来固态盘发展到高水平，也难以全部替代机械盘的位置。
4 y5 w: J2 v* j7 v# @- g, i" f0 c. F目前固态盘相比机械盘的缺点，除了价格，单位存储体积方面，还有就是单位存储功耗。一块64G的固态盘，功耗约为2W，也即是0.031W / G，而一块750G的SATA盘，最大功耗也就13W，也即0.0173W / G。