2、Microprocessor chips

2、Microprocessor chips
Chip capacities are often expressed in word sizes.Aword is the number of bits(such as
16,32,or 64)that can be accessed at one time by the CPU.The more bits in a word,the more
powereful-and the faster-the computer is.As mentioned previously,eight bits group together
to form a byte.A 32-bit-word computer access 4 bytes at a time.A 64-bit-word computer can
access 8 bytes at a time.Therefore,the computer designed to process 64-bit words is faster.
Older microcomputers typically process data and instructions in millionths of a second or
microseconds.Newer microcomputers are much faster and process data and instructions in
billionths of a second,or nanoseconds.Supercomputers,by contrast,operate at speeds
measured in picoseconds-1000 times as fast as microcomputers(See Figure 1-7).
The two most significant recent developments in microprocessors are the 64-bit processor
and the dual-core chip.Until recently,64-bit processors are becoming commonplace in today's
more powerful microcomputers.
A new type of chip,the dual-core chip,can provide two separate and independet CPUs.
These chips allow a single computer to run two programs at the same time.For example,access
could be searching a large datbase while the end user is creating a multimedia presentation
with PowerPoint.More significantly,however,is the potential for microcomputers to run very
large complex programs that perviouly were run only on mainframe and supercomputers.This
requires specifically designed programs that are divided into parts that each CPU could
process independently.This approach is called parallel processing.

2、Microprocessor chipsChip capacities are often expressed in word sizes.
2、微处理器芯片容量通常用字大小表示。
Aword is the number of bits(such as 16,32,or 64)that can be accessed at one time by the CPU.
字是CPU可以一次访问的位数(如16,32或64。
The more bits in a word,the more powereful-and the faster-the computer is.
一个词中的比特越多，计算机就越强大，而且越快。
As mentioned previously,eight bits group together to form a byte.
如前所述，八位组在一起形成一个字节。
A 32-bit-word computer access 4 bytes at a time.
一台32位字的计算机每次访问4字节。
A 64-bit-word computer can access 8 bytes at a time.
一台64位字的一次可以访问8字节。
Therefore,the computer designed to process 64-bit words is faster.
因此，设计用于处理64位单词的计算机速度更快。
Older microcomputers typically process data and instructions in millionths of a second or microseconds.
较老的微型计算机通常在百万分之一秒或微秒内处理数据和指令。
Newer microcomputers are much faster and process data and instructions in billionths of a second,or nanoseconds.
新的微型计算机速度要快得多，处理数据和指令的时间是十亿分之一秒，也就是纳秒。
Supercomputers,by contrast,operate at speedsmeasured in picoseconds-1000 times as fast as microcomputers(See Figure 1-7).
相比之下，超级计算机的运行速度是微型计算机的1000倍（见图1-7）。
The two most significant recent developments in microprocessors are the 64-bit processor and the dual-core chip.
微处理器最近的两个最重要的发展是64位处理器和双核芯片。
Until recently,64-bit processors are becoming commonplace in today's more powerful microcomputers.
直到最近，64位处理器在当今更强大的微型计算机中变得越来越普遍。
A new type of chip,the dual-core chip,can provide two separate and independet CPUs.
一种新型的芯片，即双核芯片，可以提供两个独立的CPU。
These chips allow a single computer to run two programs at the same time.
这些芯片允许一台计算机同时运行两个程序。
For example,access could be searching a large datbase while the end user is creating a multimedia presentation with PowerPoint.
例如，当最终用户使用Power Point创建多媒体演示时，访问可以搜索大型数据库。
More significantly,however,is the potential for microcomputers to run very large complex programs that perviouly were run only on mainframe and supercomputers.
然而，更重要的是，微型计算机有可能运行非常大的复杂程序，通常只在主机和超级计算机上运行。
This requires specifically designed programs that are divided into parts that each CPU could process independently.
这需要专门设计的程序，这些程序被划分为每个CPU可以独立处理的部分。
This approach is called parallel processing.
这种方法称为并行处理。

2、 微处理器芯片
芯片容量用字长表示。字是CPU一次可以访问的位数（如16、32或64），一字的位数越多，计算机的功能就越强，速度就越快。正如前面所提掉的，8位组成一字节。32为的计算机一次可以访问4字节。64位的计算机一次可以访问8字节，因而能处理64位字的计算机是更快的。
早期的微机每秒钟处理几百万个数据和指令，或称微秒级。比较新的微机处理数据和指令更快，为每秒几十亿个或称毫微秒级。相比之下，超级计算机运算速度以皮秒度量，速度比微型机快千倍以上，如图1-7所示。
微处理器两个最新最重要的发展是64比特处理器和双核芯片。直到最近，64比特处理器只用于大型和超级计算机中。而当64比特处理器在当今功能较强的微机中都在使用时，就表明一切都在变化之中。
这种新型双核芯片有两个分开且独立的CPU。这些芯片允许一台计算机在同一时间运行两道程序。例如，在端用户用PowerPoint去制作多媒体演示文稿时，另一程序可同时搜索一个大型数据库。而更重要的功能是以前只能在大型和超级计算机上运行的非常复杂的程序也可以在微机上运行。这要求吧程序专门设计成可以在每个CPU上单独处理的两部分。这种方法称为并行处理。