二、Microprocessor chips

二、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.

二、Microprocessor chipsChip capacities are often expressed in word sizes.
二、微處理器芯片容量一般用字大小表示。
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能夠一次訪問的位數(如16,32或64。
The more bits in a word,the more powereful-and the faster-the computer is.
一個詞中的比特越多，計算機就越強大，並且越快。
As mentioned previously,eight bits group together to form a byte.
如前所述，八位組在一塊兒造成一個字節。
A 32-bit-word computer access 4 bytes at a time.
一臺32位字的計算機每次訪問4字節。
A 64-bit-word computer can access 8 bytes at a time.
一臺64位字的一次能夠訪問8字節。
Therefore,the computer designed to process 64-bit words is faster.
所以，設計用於處理64位單詞的計算機速度更快。
Older microcomputers typically process data and instructions in millionths of a second or microseconds.
較老的微型計算機一般在百萬分之一秒或微秒內處理數據和指令。
Newer microcomputers are much faster and process data and instructions in billionths of a second,or nanoseconds.
新的微型計算機速度要快得多，處理數據和指令的時間是十億分之一秒，也就是納秒。
Supercomputers,by contrast,operate at speedsmeasured in picoseconds-1000 times as fast as microcomputers(See Figure 1-7).
相比之下，超級計算機的運行速度是微型計算機的1000倍（見圖1-7）。
The two most significant recent developments in microprocessors are the 64-bit processor and the dual-core chip.
微處理器最近的兩個最重要的發展是64位處理器和雙核芯片。
Until recently,64-bit processors are becoming commonplace in today's more powerful microcomputers.
直到最近，64位處理器在當今更強大的微型計算機中變得愈來愈廣泛。
A new type of chip,the dual-core chip,can provide two separate and independet CPUs.
一種新型的芯片，即雙核芯片，能夠提供兩個獨立的CPU。
These chips allow a single computer to run two programs at the same time.
這些芯片容許一臺計算機同時運行兩個程序。
For example,access could be searching a large datbase while the end user is creating a multimedia presentation with PowerPoint.
例如，當最終用戶使用Power Point建立多媒體演示時，訪問能夠搜索大型數據庫。
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，微型計算機有可能運行很是大的複雜程序，一般只在主機和超級計算機上運行。
This requires specifically designed programs that are divided into parts that each CPU could process independently.
這須要專門設計的程序，這些程序被劃分爲每一個CPU能夠獨立處理的部分。
This approach is called parallel processing.
這種方法稱爲並行處理。

二、 微處理器芯片
芯片容量用字長表示。字是CPU一次能夠訪問的位數（如1六、32或64），一字的位數越多，計算機的功能就越強，速度就越快。正如前面所提掉的，8位組成一字節。32爲的計算機一次能夠訪問4字節。64位的計算機一次能夠訪問8字節，於是能處理64位字的計算機是更快的。
早期的微機每秒鐘處理幾百萬個數據和指令，或稱微秒級。比較新的微機處理數據和指令更快，爲每秒幾十億個或稱毫微秒級。相比之下，超級計算機運算速度以皮秒度量，速度比微型機快千倍以上，如圖1-7所示。
微處理器兩個最新最重要的發展是64比特處理器和雙核芯片。直到最近，64比特處理器只用於大型和超級計算機中。而當64比特處理器在當今功能較強的微機中都在使用時，就代表一切都在變化之中。
這種新型雙核芯片有兩個分開且獨立的CPU。這些芯片容許一臺計算機在同一時間運行兩道程序。例如，在端用戶用PowerPoint去製做多媒體演示文稿時，另外一程序可同時搜索一個大型數據庫。而更重要的功能是之前只能在大型和超級計算機上運行的很是複雜的程序也能夠在微機上運行。這要求吧程序專門設計成能夠在每一個CPU上單獨處理的兩部分。這種方法稱爲並行處理。