1.2 Eight Great Ideas in computer Architecture

1.2 Eight Great Ideas in computer Architecture 计算机体系结构的八大思想

 

We now introduce eight ideas that computer architects have been invented in the last  60 years of computer design. 

现在， 我们介绍八种思想： 被计算机设计师60年前设计计算机时发明。

一.architec  CET4  /arkitəkt/  

1. N-count 可数名词 An architect is a person who designs buildings. 建筑师

2. N-count 可数名词 The architect of an idea, event, or institution is the person who invented it or made it happen. 设计师； 缔造者； 

James Madison was the principal architect of the constitution. 詹姆斯 麦迪逊 是该宪法的主设计师。 

The ideas are so powful they have lasted long after the first computer that used them, with newer architects demonstrating their admiration by imitating their predecessors. 

二. pre-decessor /prə disəsə/  CET6  pre-decessor

1. N-count 可数名词 Your predecessor is the person who had your job before you. 前任

He maintained that he learned everything he knew from his pre-decessor. 他坚称他所知道的一切都是从他的前任儿学到的。

2. N-count 可数名词 The predecessor of an object or machine is the object or machine that came before it in a sequence or process of development.前一代；

Although the car is some 2 inches shorther than its pro-decessor, its trunk is 20 percent larger. 尽管这款汽车比其上一代产品短2英寸，但它的行李箱大了20%。

三. admiration //

1. N-uncount 不可数名词  admiration is a feeling of great liking and respect for a person or thing. 钦佩；

I have always had the greatest admiration. 我对他一直怀有最大的钦佩。

四. imitate //  CET 4  imitates ,imitated imitating

 

1. V-T 及物动词： If you imitate someone, you copy what they do or produce. 模仿

...  a genuine German musical that does not try to imitate the American model.

... 一部不试图模仿美国模式的正宗德国音乐剧。

2. V-T 及物动词

If you imitate a person or animal, you copy the way they speak or behave, usually because you trying to be funny. 学...的样；常为逗乐；

Clarence screws up his face and imitates the colonel again.

克拉伦斯又板起面孔，模仿上校的样。

五. demonstrate // CET4  demonstrates  demonstrating demonstrated

1. V-T 及物动词 To demonstrate a fact means to make it clear to people.  证明

The study also demonstrated a direct link between obesity and mortality. 这项研究也证明了肥胖和死亡率之间的直接关系。

They are anxious to demonstrate to the votes that they have practical policies. 他们急于向选民证明他们有切实可行的政策。

2. V-T 及物动词 If you domonstrate a particular skill, quality, or feeling, you show by your actions that you have it. 展现才能、品质、感情；

Have they, for example, demonstrated a commitment to democracy? 例如， 他们展现了对民主的奉献吗？

3. VI不及物动词  When people demonstrate, they march or gather somewhere to show their opposition to something or their support for something. 游行示威

Some 30,000 angry farmers arrived in Brussels yesterday to demonstrate against possible cuts in subsidies. 昨天，大约三万名愤怒农民到布鲁塞尔游行示威，反对可能的补贴削减。

In the cities vast crowds have been demonstrating for change. 在各城市，已经有大量的群众举行游行示威，要求变革。

4. VT 及物动词 If you demonstrate something, you show people how it works or how to do it. 展示

A selection of cosmetic companies will be there to demonstrate their new products. 一些化妆品公司会在哪里展示他们的新产品。

 

These great ideas are themes that we will weave through this and subsequent chapters as examples arise.

六. arise CET4 /əraiz/ 

1. VI 不及物动词 If a situation or problem arises, it begins to exsit or people start to become aware of it. 出现

...  if a problem arises later in the pregnancy.

... 如果在怀孕后期出现问题。

2. VI不及物动词

If something arises from a particular situation, or arises out of it, it is created or caused by the situation. 产生；由...

This  serenity arose in part from Rachel's religious beliefs.

这种平和部分由于雷切尔的宗教信仰。

七.  subsequent  CET4  /səbsikwənt/ 1. adj. 形容词 Formal  正式

You use subsequent to describe something that happened or existed after the time or event that has just been referred to. [adj + n ] 随后的

'... the increase of population in subsequent years. 随后几年中的人口增长。

sub+se+quent+ly 　　adv. 副词　　后来

He subsequently worked on Boeing's 747, 767 and 737 jetliner programs.

他后来从事了波音747 、767和737 喷气式飞机的项目。

八. weave /wiv/ CET 4   The form weaved is used for the past tense and past participle for meaning 3.

If  you weave cloth or a carpet, you make it by crossing threads over and under each other using a frame or machine called a loom. 织

They would spin and weave cloth,coock and attend to domestic side of life. 他们纺纱、织布、做饭、还料理家务。

wo+ven  adj. 形容词　　编织的

... woven cotton fabrics. ... 棉织物

weaving 　　N+uncounting 不可数名词

When I studies weaving, I became intrigued with natural dyes. 在我学习编织的时候，对天然染料发生了兴趣。

VT 及物动词

If you weave something such as  a basket, you make it by crossing long plant stems or fibers over and under each other. 编织篮子等

Jenny weaves baskets from willow she grows herself. 珍妮用自己栽种的柳树的枝条编织篮子。

wo+ven 　　adj. 形容词　　编织的

The floors are covered with woven straw mats. 地板上铺着用草编织的垫子。

VT /VI 及物动词/不及物动词

If you  weave your way somewhere, you move between and around things as you go there. 迂回行进

The cars then weaved in and out of traffic at top speed. 汽车然后在车流中高速穿梭前进。

He weaved around the tables to where she sat with Bob.他在桌子间穿梭走动，来到她和鲍勃坐的地方。

To point out their influence, in this section we introduce icons and highlighted terms that represent the great ideas and we use them to identify the nearly 100 sections of the book that feature use of the great ideas.

九. icon　　CET 6 /aikɔn/ icons

1. N-count 可数名词

If you describe something or someone as an icon, you mean that they are important as a symbol of a particular thing. 象征物；偶像

... only Marilyn has proved as enduring a fashion icon. ... 只有玛丽莲被证明是经入不衰的时尚偶像。

2. N-count 可数名词

An icon is a picture of Christ, his mother. or a saint painted on a wooden panel. 木制圣像， 耶稣基督、圣母玛丽亚等圣人的

... a painter of religious icons ... 一位宗教圣像画家。

3.N-count 可数名词 Computer 计算机

An icon is a picture on a computer screen representing a particular computer  function. If you want to use it, you move the cursor onto the icon using a mouse. 图标 电脑屏幕上可用鼠标点击的

Kate clicked on the mail icon on her computer screen.

凯特点击了她电脑屏幕上的邮件图标。

十. Influence /infl/  CET 4  influences influencing influenced

1. N-uncount 不可数名词

Influence is the power to make other people agree with your opinions or do what you want. 权势

He used his influence to get his son into medical school. 他利用权势把儿子弄进了医学院。

He denies exerting any political influence over them. 他否认曾向他们施加过政治影响。

2. VT 及物动词

If you influence someone, you use your power to make them agree with you or do what you want. 影响　　

He is trying to improperly influence a witness.他正试图不适当地影响一名证人。

3. N-count  可数名词

To have an influence on people or situations means to affect what they do or what happens. 影响

Van Gogh had a major influence on development of modern painting. 凡高对现代绘画的发展有着重大的影响。

4. vt  及物动词

If someone or something influences a person or situation, they have an effect on that person's behavior or that situation. 影响

We became the best friends  and he influenced me deeply. 我们成为最好的朋友，而他深深地影响着我

5. N-count 可数名词

Someone or something that is a good or bad influence on people has a good or bad effect on them.  有影响的人或事物

I thouth Sonny would be a good influence on you. 我认为桑尼对你会有好的影响。

6. PHRASE  习语

If you are under the influence of someone or something, you are being affected or controlled by them. 在... 影响之下：

He was arrested on suspicion of driving under influence of alcohol. 他因涉嫌酒后驾车而被捕。

 

Design for Moore's Law

 

The one constant for computer designers is rapid change, which is driven largely by Moore's Law.

It states that integrated circuit resources double every 18-24 months.

Moore's Law resulted from a 1965 prediction of such growth in IC capacity made by Gordon Moore, one of the founders of Intel.

As computer designs can take years, the resources available per chip can easily double or quadruple between the start and finish of the project.

Like a skeet shooter, compter architects must anticipate where the technology will be when the design finishes rather than design for where it starts.

we use "up and to the right" Moor's Law graph to represent designing for rapid change.

十一. constant  CET4 /Kɔstənt/

1. adj 形容词 You use constant to describe something that happens all the time or is always there. 常发生的；常存在的；

She suggests that women are under constant pressure to be abnormally thin. 她提出女性受持续的压力之下要异常苗条。

Inflation is a constant threat. 通货膨胀是一种持续的威胁。

con + stant+ly  adv 副词 持续不断地

The direction of the wind is constantly changing. 风的方向在不断地变。

If an amount or level is constant, it stays the same over a particular period of time. 保持不变的在某段时间内； 

The body feels hot and the temperature remains more or less constant at the new elevated level. 身体感到热，可体温保持在升高后的新高度上差不多稳定不变。

You can use constant, continual, and continous to describe things that happen or exist without stopping. You  describe something as constant when it happens all the time or never goes away. He was in constant pain... Eva's constant criticism. Continual is usually used to describe something that happens often over a period of time, especially something undersirable... his continual drinking, ... continual demands to cut costs. If something is continuous, it happens all  the time without stopping, or seems to do so... days of continuous rain. ... a continuous  background noise.

十二.  rapid /ræpid/  CET 4 

1. adj. 形容词 A rapid change is one that happens very quickly. 快速的变化；

... the country's rapid economic growth in the 1980s.  ... 这个国家在20世纪80年代快速的经济增长

rap+id+ly

ADV 副词 快速地

... countries with rapidly growing populations. ...人口快速增长的国家。

Try to rip it apart as rapidly ass possible.试着尽快把它撕开。

ra+pid+ity /rəpidti/ N-uncount 不可数名词 快速

... the rapidity with which the weather can change. ...天气以极速的速度发生变化。

adj.  形容词 A rapid movement is one that is very fast. 迅速的动作

He walked at a rapid pace along Charles Street. 他沿着查尔斯大街快步行走。

rap+id+ly  ADV 副词 [adv with ] 迅速地

He was moving rapidly around the room. 他正在房间里快速地来回走着！

ra+pid+ity N-count 不可数名词　　迅速

The water rushed through the holes with great rapidity. 水流急速地冲过这些洞口。

十三. prediction /pridikʃən/  predictions

1. N-var  有变体名词

If you make a prediction about something, you say what you think will happen. 预言

He was unwilling to make a prediction for the coming year.他不愿对来年作出预言。

Weather prediction has never been a perfect science. 天气预报从来不是一门准确无误的科学。

十四.  quadruple /kwɔdrupəl/ 

1. VT /VI  及物动词、不及物动词 If someone quadruples an amount or if it quadruples, it becomes four times bigger. 使成四倍。

China seeks to quadruple its income in twenty years. 中国力求20年内将其收入翻两番。

2. PREDET 前置限定词 If one amount is quadruple another amount, it is four times bigger. (PREDET det 4 ) 4 倍的

Fifty-nine percent of its residents have attended graduate school quadruple the national average. 该地区59%的居民读过研究生是全国平均水平的4倍。

3. adj. 形容词

You use quadruple murder has replaced  property prices as the sole topic of interest.

这4起连环谋杀案已经取代房价成为人们惟一感兴趣的话题。

 

 

 

 

use Abstraction to simplify design

 

Both computer architects and programmers had to invent techniques to make themselves more productive, for otherwise design time would lengthen as dramatically as resources by Moore's Law.

A major productivity technique for hardware and software is to use abstractions to represent the design at different levels of representation; lower-level details are hidden to offer a simpler model at high levels.

We'll use the abstract painting icon to represent this great idea.

 

dramatically /drə'mætikli/  adv. 戏剧地；显著地；

1. in a way that grabs the attention and causes an excited, shocked, or startled reaction

2. to a very noticeable degree and often with surprising suddenness.

productivity/,prɔdʌk'tivəti/ n. 生产率；生产效率；

1.  productivity is the rate at which goods are produced. = output

 

Make the common case Fast

 

Making the common case fast tend to enhance performance better than optimizing the rare case.

Ironically, the common case is often simpler than the rare case and hence is often easier to enhance.

This common sense advice implies that you know what the common case is, which is only possible with careful experimentation and measurement (see section 1.6).

We use a sports car as the icon for making the common case fast, as the common trip has one or two passengers and it's surely easier to make a fast sports car than a fast minivan.

 

Performance via parallelism

 

 

Since the dawn of computing, computer architects have offered designs that get more performance by performing operations in parallel.

We'll see many examples of parallelism in this book.

We use multiple jet engines of a plane as our icon for parallel performance.

 

 

Performance via pipelining

 

A particular pattern of parallesim is so prevalent in computer architecture that it merits its own name: pipelining.

For example, before fire engines, a "bucket brigade" would respond to a fire, which many cowboy movies show in response to a dastardly act by the villain.

The townsfolk form a human chain to carry a water source to fire, as they could much more quickly move buckets up the chain instead of individuals running back and forth.

Our pipeline icon is a sequence of pipes, with each section representing one stage of the pipeline.

 

Performance via prediction

 

Following the saying that it can be better to ask for forgiveness than ask for permission, the final great idea is prediction.

In some cases it can be faster on average to guess and start working rather than wait until you know for sure, assuming that the mechanism to recover from misprediction is not too expensive and your prediction is relatively accurate.

We use the fortune-teller's crystal ball as our prediction.

 

crystal /kristl/ adj. 晶莹的；如水晶般的；清楚的；显而易见的；

1.  A crystal is a small piece of substance that has formed naturally into a regular symmetrical shape. 水晶球！

2.  Crystal is a transparent rock that is used to make jewellery and ornaments.

3.  Crystal is a high quality glass, usually with patterns cut into its surface.

4. Glasses and other containers made of crystal are referred to as crystal

 

Hierarchy of Memories

 

Programmers want memory to be fast, large and cheap, as memory speed often shapes performance, capacity limits the size of problems that can be solved, and the cost of memory today is often the majority of computer cost.

Architects have found that they can address these conflicting demands with a hierarchy of memories,  with the fastest, smallest, and most expensive  memory per bit at the top of the hierarchy and the slowest, largest, and cheapest per bit at the bottom.

As we shall see in chapter 5, caches give the programmer the illusion that main memory is nearly as fast as the top of the hierarchy and nearly as big and cheap as the bottom of the hierarchy.

We use a layered triangle icon to represent the memory hierarchy.

The shape indicates speed, cost , and size: the closer to the top, the faster and more expensive per bit the memory; the wider the base of the layer, the bigger the memory

hierarchy /' haiə,ra:ki/  n. 层次体系；等级制度（尤指社会或组织）；统治集团；

1. N-var usu with supp　　A hierarchy is a system of organizing people into different ranks or levels of  importance, for example, in a society or in a company.

2. N- count-coll   with supp  The hierarchy organization such as church is the group people who manage and control it.

3. N-count usu N of n   A hierarchy of ideas and beliefs involves organizing them into a system or structure. (Formmal) 

 

 

Dependability via Redundancy

 

Computers not only need to be fast; they need to be dependable.

Since any physical device can fail, we make systems dependable by including redundant components that can take over when a failure occurs and to help detect failures.

We use the tractor-trailer as our icon, since the dual tires on each side of its rear axles allow the truck to continue driving even when one tire fails.

( Presumably, the truck driver heads immediately to a repair facility so the flat tire can be fixed, thereby restoring redundancy!)

presumably /pri'zju:məbli/ adj. 大概；很可能；想必是：

If you say that something is presumably the case, you mean that it is very likely to be the case, although you are not certain.

thereby/ðeə'bai/ adv. 从而；因此；由此；

You use thereby to introduce an important result or consequence of event or action you have just mentioned. = thus

tractor /'træktə/ n.  A tractor is a farm vehicle that is used to full farm machinery to provide the energy needed for machinery to work  拖拉机；牵引机；拖车头

trailer/'treilə/ n.挂车；拖车；活动工作室；（电影或电视节目的）预告片；

1.n-count   A trailer is one container on wheels which is pulled by a car or other vehicle and which is used for transporting large or heavy item.

2. n-count  A trailer is the long rear section of a larry or truck, in which the goods are carried.

3. n-count  A trailer is a long vehicle without engine which people use as a home or as an office and which can be pulled behind a car

4. n-count  A trailer for a film or television programme is a set of short extracts which are shown to advertise it.

dual /dju：əl/ adj. 两部分的；双重的；双的； dual means having two parts, functions, or aspect.

rear /'riə/  adj. 后面的；后部的

1. N-sing  the N, usu  N of n   The rear of sometthing such as building or vehicle is the back part of it. = back

Rear is also adjective.

2. N-sing  the N  usu  N of n  If you are at the rear of a moving line of people, you are last person in it. (Formal)= back

3. N-count  usu poss N  Your rear is the part of your body that you sit on.(Formal)= behind;

4. VERB   v n    If you rear children, you look after them until they are old enough to look after themselves. = bring up ; raise;

5. VERB 　v n    If you rear a young animal, you keep and look after it until it is old enough to be used for work or food, or until it can look after itself. (mainly BRIT; in AM usually use raise )

6. VERB 　　V 　　When a horse rears, it moves the front part of its body upwards, so that its front legs are high in the air and it is standing on its back legs.

7. VERB      V    If you say that something such as building or mountain rears above you, you mean that is very tall or closed to you. = loom

8.  PHRASE   If a person or vehicle is bringing up thr rear, they are last person or vehicle in a moving line of them.

 tire /taiə/ n. 轮胎；车胎；

detect /di'tekt/ v. 发现；查明；侦测

1. verb   v n ; v + wh--;  To detect something means to find it or discover that it is present somewhere by using equipment or making a investigation.

2. verb  v n; If you detect something, you notice it or sense it, even though it is not very obvious. = sense;