機械硬盤---討論

easylife

Key Technological Firsts

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.
, `: ?1 D( x7 Q3 ?3 PFirst 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%.
First 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.
First 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.
: i0 p) E# G0 K/ V) Y+ k. U. wFirst 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.
5 L7 i* Y- Y2 C1 i3 Z5 fFirst 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.
First 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.
8 w5 J9 r  R- q, JFirst 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.
) [) A' a4 R! z  S( ]First 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.
1 N& J+ K% v# b0 tFirst "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.
/ e2 h0 I( ]4 i4 X4 NFirst 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.
8 Y# w! G/ ]- H5 k5 H6 wFirst 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.
First 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.
* n! X+ s' f' ^5 UFirst 1.3" Form Factor Disk Drive (1992): Hewlett Packard's C3013A is the first 1.3" drive.
  Z3 P1 \" Y3 }4 VThe 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

關鍵的"技術第一":
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在硬盤界過去的40多年里產生了許多重要的“第一”，接下來的是一個按時間先后順序的列表,列舉出了在過去近半個世紀個人電腦世界里一些產品開發關鍵技術。請留意IBM在列表中醒目的主導地位，根據作者的觀點，藍色巨人并沒有得到與其在存儲業界所做貢獻相稱的認可。同時也請注意她花了多少年時間才使硬盤進入個人電腦（有時候多達10年之久，都歸于大部分新技術高昂的初期成本）。

第一個硬盤（1956）： 發明IBM的RAMAC。 容量5MB，存儲在50張25英寸的盤片上。它的面密度僅僅只有大概2，000字節每平方英寸，而且它的數據傳輸速度是8，800字節每秒。
" Z7 \) Y- t, _0 K0 H; Q0 a5 w第一個空氣軸承磁頭（1962）：IBM的1301將飛行高度降低到250微英寸，它擁有28MB容量，磁頭數目只有初期RAMAC磁頭數目的一半，并且將磁面密度提高了一倍，數據速度提高10倍。
$ I7 [- K) U+ c7 a# A第一個可移動硬盤（1966）：IBM的2310是第一個具有可可移動封裝的硬盤。而大多數電腦使用者認為可移動硬盤是現代的發明，實際上在20世紀60和70年代之間是非常流行的。
' G( T  Z, U8 p7 K第一個鐵氧體磁頭（1979）：IBM的2314是第一個使用鐵氧體磁心磁頭的硬盤，這種磁頭是第一種使用在個人電腦硬盤中的磁頭。
) R) j5 w$ ?  [6 d9 {  T第一個現代硬盤設計（1973）： IBM推出3340，別名“溫徹斯特” ，60MB容量，它引進一些關鍵的硬盤技術，被后來許多的現代硬盤的雛形所參考和引用。
# f/ V; h: c! Y" W% I第一個薄膜磁頭（1979）： IBM的3370首先采用了薄膜磁頭，之后多年一直是個人電腦硬盤的標準。
8 Z: N; I1 V1 j: M' G4 ~第一個8英寸硬盤（1979）： IBM的3310是第一個配備8英寸盤片的硬盤，它將硬盤的尺寸從14英寸有效地減小到了8英寸，并一度保持了業界標準尺寸達10之久。

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, ^& h( \3 X; F6 r2 O# O( {第一個5.25英寸硬盤（1980）：Seagate 的ST-506是第一個5.25英寸硬盤，使用在最早期的個人電腦上。
第一個3.5英寸硬盤 （1983）：Rodime推出了RO352，第一個3.5英寸硬盤，成為最重要的行業標準尺寸之一。
# [# q9 d4 n: V' T4 ?- J第一個擴展卡式硬盤（1985）： Quantum推出了Hardcard，一個安裝在本來沒有硬盤的個人電腦里，固定在一張ISA擴展卡上的10.5MB的硬盤。這個產品使Quantum在儲存界獲得了好名聲。
第一個（使用）音圈制動臂的硬盤（1986）： Conner Peripherals推出了CP340, 第一個使用音圈制動臂的硬盤。
9 u. T: I8 m! d  Q% n7 Y第一個“低矮外形”的3.5硬盤（1988）：Conner Peripherals推出CP3022，它是第一個將3.5英寸硬盤高度降低到1英寸的硬盤，被稱為“低矮外形”硬盤，并成為現代3.5硬盤的標準。
第一個2.5英寸硬盤（1988）：PrairieTek推出了使用2.5盤片的硬盤，這個尺寸后來成為筆記本電腦的標準。
第一個使用磁阻磁頭和PRML解碼的硬盤（1990）： IBM的681（紅翼鶇），容量857MB，是第一個使用磁阻式磁頭和PRML的硬盤。
& N* }" ]- Q' Z/ j' T* l! e第一個薄膜碟片（1991）：IBM的“Pacifica”架構硬盤是第一個取代氧化物碟片的驅動器，其盤片涂敷的是薄膜磁性物質。
% O* T. F: B2 S+ k* E. }3 Y第一個1.5英寸硬盤（1991）： Integral Peripherals的1820是第一個1.8英寸硬盤，后來作為電腦卡式硬盤使用。
第一個1.3英寸硬盤（1992）：Hewlett Packard的C3013A是第一個1.3硬盤。

easylife

Hard Disk Trends

The 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:

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!

, h, ^* g# g- f: DCapacity: 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.

" B' Q! d' W" l7 b3 k: Q/ eSpindle 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.
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7 c; g$ k6 F' A5 u- AForm 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.

  i; @9 {5 ^" U9 Q0 u2 y# g- @8 k% JPerformance: 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.
. \# P5 u' Z# U% U5 o# qReliability: 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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RAID: 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.
Interfaces: 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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8 h9 }: K/ o' y/ C[ 本帖最后由 easylife 于 2008-11-23 23:29 編輯 ]

龍游大海

結構原理上來說硬盤是一個簡單的機械產品.有硬盤結構圖嗎？發一個上來

easylife

原帖由 龍游大海 于 2008-12-7 09:48 發表
結構原理上來說硬盤是一個簡單的機械產品.有硬盤結構圖嗎？發一個上來

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/ q' b, @9 G9 L: m我想這樣描述更合適, "從外觀形式來說,硬盤似乎是一個簡單的機械產品.".
. n- t6 I2 v' s+ F  V8 C! ]" Q----個人認為機械硬盤是20世紀工程界一個偉大的發明, 高度集成的機電產品.融合了磁記錄,wafer制造和切割(磁頭),精密機械設計(包括大量振動問題,液體動壓軸承,電磁分析),精密servo控制,pcb設計, firmwave.
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- f9 Z! H+ F3 p2 r( p( t舉個例子, 機械部分壓緊碟片的零件(clamp)設計,要求其能壓緊碟片,保證硬盤在承受水平方向1000G左右的沖擊時碟片不發生移動,或豎直方向1000G沖擊(跌落)時碟片不能碰到其他零件,這樣就要求clamp安裝壓緊后的緊固力足夠大.
但是, 我們希望碟片被clamp壓緊后變形(flatness)盡可能小,一般在幾個微米左右.這樣就要求clamp緊固后壓緊力也不能太大, 否則導致硬盤工作時磁頭工況惡劣,甚至不能正常工作.
7 ?. T( Z# _. x, V( R綜上所敘,clamping force是在一定范圍內的,至于nominal value,tolerance,需要計算,仿真,考慮加工工藝和關鍵尺寸CPK情況.
毫不夸張的說,一個零件設計足夠做一個博士課題

( `" J. `2 }3 s* b7 _# [[ 本帖最后由 easylife 于 2008-12-16 23:59 編輯 ]

easylife

整理了一份關于其歷史的文檔, 資料來自于以下連接
http://www.pcshow.net/detail-36-427685-2.html

" H/ y7 ~: V: @% T& Y0 b* y4 F  R祝大家新年快樂!

easylife

某大學收藏的硬盤, 很難想象以前的硬盤能重大幾百公斤甚至數噸

長弓宏

世界幾大硬盤企業都在中國有全工藝流程的工廠
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東莞的新科(SAE TDK的子公司)
7 s1 F# Z. V$ J# R深圳的日立
/ I9 }& z& m# Q! U7 l9 M) [蘇州的希捷
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8 b' s( T  u, ~2 j7 `/ X$ B都有高等級的無塵室
3 |! }6 N' w/ m3 Z3 r* |8 z( y更不用說那些IC制造商比如和艦 中芯 海力士
& U: T: }1 q; S7 U無塵室系統全是國外造的  但是是能進口到中國的
5 |2 k& F% z9 u( z  t無塵室的桌子 凳子 筆 推車 人穿的衣服等等任何東西都要接地防靜電 每天都要做塵粒測試和靜電測試

easylife

原帖由 長弓宏 于 2009-1-6 20:05 發表
世界幾大硬盤企業都在中國有全工藝流程的工廠

東莞的新科(SAE TDK的子公司)
: O6 B; A- J& S7 T$ t深圳的日立
蘇州的希捷
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7 P# m7 h! ?/ Q+ i# d都有高等級的無塵室
% w' Q1 ]/ `2 K) l0 f更不用說那些IC制造商比如和艦 中芯 海力士
無塵室系統全是國外造的  但是是能進口到 ...

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朋友了解得還不少
不過我沒有見過出于防靜電需要的筆還需要接地的，一般書寫的筆采用特制的耗散性材料---半導體，不易產生靜電，導電也較快。

% a2 k+ {1 r8 C% d8 W* [) a聽說一套無塵室使用的內六角扳手需要1萬多美元（沒有證實過）。。

紫木棉

機械磁盤在最近十幾年的發展，可以說是突飛猛進。但就是這樣的發展，磁盤也沒有把磁帶機掃入歷史的垃圾堆里，直到現在，磁帶機依舊在不少地方發揮作用。所以個人覺得，即使將來固態盤發展到高水平，也難以全部替代機械盤的位置。
目前固態盤相比機械盤的缺點，除了價格，單位存儲體積方面，還有就是單位存儲功耗。一塊64G的固態盤，功耗約為2W，也即是0.031W / G，而一塊750G的SATA盤，最大功耗也就13W，也即0.0173W / G。