Cache Memory

• Program and data are loaded to RAM from secondary storage because the time required to access a program instruction or piece of data from RAM is significantly less than from secondary storage.

- program and data 程序和数据
- be loaded to 被加载到
- secondary storage 二级存储器
- the time required 所需的时间
- access a program instruction 访问程序指令
- piece of data 数据片/数据段
程序和数据从辅助存储器加载到RAM中，因为从RAM中访问程序指令或数据所需的时间比从辅助存储器中访问要少得多。

• RAM is essentially a high-speed holding area for data and programs.

RAM本质上是一个高速存储数据和程序的区域。  
- essentially 本质上 

- a high-speed holding area for data and programs

• In fact, nothing really happens in a computer system until the program instructions and data are moved to the processor.

- nothing really happends 什么都不会发生

• This transfer of instruction and data to the processor can be time-consuming, even at microsecond speeds.

- transfer 转移   eg: technology transfer 技术转移  transfer coefficient 转移系数
- time-consuming adj. 耗时的；旷日持久的  eg:  a time-consuming job 耗时的工作； 耗时的任务
- microsecond n. 微妙

• To facilitate an even faster transfer of instructions and data to the processor, most computers are designed with cache memory.

- facilitate v. 使更容易；促进；推动

• Cache memory is employed by computer designers to increase the computer system throughput(the rate at which work is performed).

- be employed by 被雇佣
- computer designers 计算机设计师
- computer system throughput  计算机系统吞吐量
- the rate at which work is performed. 完成工作的速率

• With only a fraction of the capacity of RAM, cache memory holds only those instructions and data that are likely to be needed next by the processor.

- a fraction of 一小部分；一部分
- the capacity of ... ...能力；....容量
- cache memory 高速缓冲存储器
- instructions and data 指令和数据
- be likely to be 很有可能

• Two types of cache memory appear widely in computers

- two types of cache memory 两种类型的高速缓冲存储器
- appear widely in computers 广泛出现在电脑中

• The first is referred to as internal cache and is built into the CPU chip.

- be referred to 被提及
- internal cache 内部缓存
- be built into 使成为（计划、系统或协议的）组成部分

• A computer can have several different levels of cache memory.

- several different levels of  几个不同的水平
一台计算机可以有几个不同级别的高速缓存存储器。  

Words and Expressions

* processor n. 处理机  - signal processor 信号处理机
* primary storage 主存储器
* scores of 许多  - scores of years ago 许多年前
* control unit 控制部件
* arithmetic and logic unit 算数逻辑部件
* integral parts 不可缺的部分,  
* tape and disk 磁盘和磁带
* a state of the art(the state of the art) 目前工艺水平,最新发展水平
* chip n. 炸薯条、芯片
* secondary storage 辅助存储器；二级存储器   
* income reallocate 收入再分配
* at a premium 非常珍贵
* location n. 单元，位置
* hardwired adj. 硬接线的
* read-mostly adj. 以读为主的
* nonvolatility n. 非易失性的
* updatable adj. 可修改的
* funcionality n. 功能性；函数性
* throughput capacity 生产能力
* be referred to as 称作，叫做
* expansion n. 扩充；扩展
* slot n. 插槽
* power supply 电源；供电
* floppy n. 软盘
* literally 不加夸张的讲；确实
* retrieve the appropriate 取出所需的
* initiate 启动，初始化
* SD - Secure Digital