📄 中英对照计算机性能的量度.htm
字号:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<!-- saved from url=(0073)http://bbs.csai.cn/bbs/view.asp?Id={07D0B0E8-98D5-48B4-8642-C1B7EEC9019C} -->
<HTML><HEAD><TITLE>中英对照:计算机性能的量度：希赛社区|中国系统分析师|中国系统分析员</TITLE>
<META http-equiv=Content-Type content="text/html; charset=gb2312">
<META
content=软考联盟,中国软考联盟,软考,软考论坛,软考资料,软考辅导,软考培训,考研共济网,中国考研网,考研,考研网,自学考试,计算机自考,易自考,自考办,项目管理,软件测试,软件工程,IT审计,信息化,CIO
name=keywords>
<META
content=软考联盟,中国软考联盟,软考,软考论坛,软考资料,软考辅导,软考培训,考研共济网,中国考研网,考研,考研网,自学考试,计算机自考,易自考,自考办,项目管理,软件测试,软件工程,IT审计,信息化,CIO
name=description><LINK href="中英对照计算机性能的量度_files/css.css" type=text/css
rel=stylesheet>
<STYLE>BODY {
PADDING-RIGHT: 0px; PADDING-LEFT: 0px; PADDING-BOTTOM: 0px; MARGIN: 0px; PADDING-TOP: 0px; TEXT-ALIGN: center
}
.userInfoBox {
BORDER-RIGHT: #cccccc 1px solid; PADDING-RIGHT: 2px; BORDER-TOP: #cccccc 1px solid; PADDING-LEFT: 2px; FONT-SIZE: 12px; PADDING-BOTTOM: 2px; MARGIN: 2px; BORDER-LEFT: #cccccc 1px solid; COLOR: #999999; PADDING-TOP: 2px; BORDER-BOTTOM: #cccccc 1px solid; BACKGROUND-COLOR: #ffffff
}
.TitleInfoBox {
MARGIN-TOP: -2px; FONT-SIZE: 12px; WIDTH: 98%; COLOR: #666666
}
.bbsmain {
FONT-SIZE: 14px; LINE-HEIGHT: 150%
}
#cont_right {
FONT-SIZE: 14px; OVERFLOW-X: hidden; LINE-HEIGHT: 150%
}
</STYLE>
<SCRIPT>
var resizemode=1;
function imgresize(o){
if (resizemode==2 || o.onmousewheel){
if(o.width > 500 ){
o.style.width='98%';
}
if(o.height > 800){
o.style.height='98%';
}
}else{
var parentNode=o.parentNode.parentNode
if (parentNode){
if (o.offsetWidth>=parentNode.offsetWidth) o.style.width='98%';
}else{
var parentNode=o.parentNode
if (parentNode){
if (o.offsetWidth>=parentNode.offsetWidth) o.style.width='98%';
}
}
}
}
</SCRIPT>
<META content="MSHTML 6.00.3790.2759" name=GENERATOR></HEAD>
<BODY
onmouseover="window.status='【希赛IT社区】希赛，影响IT！ 希赛网（www.csai.cn），IT领跑者！';return true">
<DIV align=center>
<DIV id=body_container
style="PADDING-RIGHT: 0px; PADDING-LEFT: 0px; PADDING-BOTTOM: 0px; MARGIN: 0px; WIDTH: 777px; PADDING-TOP: 0px; TEXT-ALIGN: center">
<DIV id=top_title
style="PADDING-RIGHT: 0px; PADDING-LEFT: 0px; PADDING-BOTTOM: 0px; MARGIN: 0px; WIDTH: 100%; PADDING-TOP: 0px"
align=center>
<SCRIPT language=javascript src="中英对照计算机性能的量度_files/title.htm"></SCRIPT>
</DIV>
<STYLE>P {
LINE-HEIGHT: 150%
}
</STYLE>
<TABLE height=22 cellSpacing=1 cellPadding=3 width=777 align=center
bgColor=#cccccc border=0>
<TBODY>
<TR vAlign=center align=middle bgColor=#f5f5f5>
<TD class=hai width=45><A class=chinahong
href="javascript:Login('http://bbs.csai.cn/prelogin.asp?page=http://bbs.csai.cn/bbs/index.asp')">登陆</A></TD>
<TD class=hai width=42><A class=Hai href="javascript:refresh();">刷新</A></TD>
<TD class=hai width=41><A class=Hai
href="javascript:NewWindow_b('Search.Asp')">搜索</A></TD>
<TD class=hai width=48><A class=hai
href="javascript:NewWindow_b('Question.Asp?Class=G7');">发新帖</A></TD>
<TD class=hai width=48><A class=hai
href="http://bbs.csai.cn/bbs/primelist.Asp?Class=G7"><FONT
color=#ff0000>精华帖</FONT></A></TD>
<TD class=hai width=48><A class=hai
href="http://bbs.csai.cn/bbs/savelist.Asp?Class=G7">收藏夹</A></TD>
<TD class=hai width=54><A class=chinahai
href="javascript:NewWindow_b('pink.Asp')">热帖</A></TD>
<TD class=hai width=65><A class=hai
href="javascript:NewWindow_b('NoResolve.Asp')">待解决帖</A></TD>
<TD class=hai width=33><A class=chinahong
href="http://bbs.csai.cn/bbs/exit.asp">退出</A></TD>
<TD class=hai width=61><A class=hai
href="javascript:NewWindow_b('help/index.asp')">社区规则</A></TD>
<TD class=hai width=58><A class=chinahai
href="http://bbs.csai.cn/shme/shortmess.asp" target=_blank>短消息</A></TD>
<TD class=hai width=100><A class=chinahong href="http://platform.csai.cn/"
target=_parent><STRONG>远程教育平台</STRONG></A></TD>
<TD class=hai width=67><A class=hai
href="javascript:window.close()">关闭窗口</A></TD></TR></TBODY></TABLE>
<DIV id=body_left
style="PADDING-RIGHT: 0px; PADDING-LEFT: 0px; FLOAT: left; OVERFLOW-X: hidden; PADDING-BOTTOM: 0px; MARGIN: 0px; WIDTH: 600px; PADDING-TOP: 0px">
<TABLE cellSpacing=0 cellPadding=0 width="100%" align=center border=0>
<TBODY>
<TR>
<TD>
<TABLE cellSpacing=1 cellPadding=0 width="100%" align=left bgColor=#6595d6
border=0>
<TBODY>
<TR>
<TD bgColor=#6595d6 height=25><IMG height=11
src="中英对照计算机性能的量度_files/newwin.gif" width=14 align=absBottom><STRONG
style="COLOR: white"> 主题：中英对照:计算机性能的量度</STRONG></TD></TR>
<TR>
<TD>
<TABLE class=hai cellSpacing=1 cellPadding=1 width="100%" align=left
bgColor=#cccccc border=0>
<TBODY>
<TR align=middle bgColor=#ffffff>
<TD width=64>作 者</TD>
<TD width=233>ok101</TD>
<TD width=63>阅读次数</TD>
<TD width=85>310</TD>
<TD width=63>回复次数</TD>
<TD width=85>7</TD></TR>
<TR align=middle bgColor=#ffffff>
<TD width=64>所属栏目</TD>
<TD width=233>基础应用与新手入门>> IT英语</TD>
<TD width=63>发表日期</TD>
<TD width=85>2006-9-1</TD>
<TD width=63>回复日期</TD>
<TD
width=85>2006-9-28</TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE></TD></TR></TBODY></TABLE>
<TABLE cellSpacing=1 cellPadding=5 width="100%" align=center bgColor=#6595d6
border=0>
<TBODY>
<TR bgColor=#e4e8ef>
<TD class=chinabai vAlign=top align=middle width=83 height=70>
<DIV align=center><IMG height=15 src="中英对照计算机性能的量度_files/vb_bullet.gif"
width=15><BR><A class=chinablue title=给他/她留言
href="http://po.csai.cn/write_shortmess.asp?func=0&username=ok101"
target=_blank>ok101</A><BR><IMG alt=等级2
src="中英对照计算机性能的量度_files/top-2.gif"><BR>
<DIV class=userInfoBox>积分：2768<BR>第二级</DIV>
<DIV class=userInfoBox>注册时间<BR>2003-5-12</DIV></DIV></TD>
<TD class=bbsmain style="WORD-BREAK: break-all; WHITE-SPACE: normal"
vAlign=top align=left bgColor=#e4e8ef height=70>
<DIV class=TitleInfoBox align=right>发表时间：2006-9-1 9:47:19 楼主</DIV>
<HR style="MARGIN-TOP: -5px; COLOR: #cccccc" align=center width="100%"
noShade SIZE=1>
<DIV id=cont_right style="WIDTH: 495px"> 1．What is a performance
metric?<BR><BR> Before we can begin to understand any aspect of a
computer system’s performance，we must determine what things are
interesting and useful to measure．The basic characteristics of a computer
system that we typically need to measure are：<BR><BR>• a count of how many
times an event occurs；<BR><BR>• the duration of some time
interval；<BR><BR>• the size of some parameter．<BR><BR>For instance，we may
need to count how many times a processor initiates an input /output
request．We may also be interested in how long each of these requests
takes．Finally，it is probably also useful to determine the number of bits
transmitted and stored．<BR><BR>From these types of measured values，we can
derive the actual value that we wish to use to describe the performance of
the system．This value is called a performance metric．<BR><BR>2．Processor
and system performance metrics<BR><BR>1）The clock rate<BR><BR>In many
advertisements for computer systems，the most prominent indication of
performance is often the frequency of the processor’ s central clock．The
implication to the buyer is that a 250 MHz system must always be faster at
solving the user’ s problem than a 200 MHz system，for
instance．However，this performance metric completely ignores how much
computation is actually accomplished in each clock cycle，it ignores the
complex interactions of the processor with the memory subsystem and the
input /output subsystem，and it ignores the not at all unlikely fact that
the processor may not be the performance bottleneck
[1]．<BR><BR>2）MIPS<BR><BR>A throughput or execution-rate performance
metric is a measure of the amount of computation performed per unit
time．Since rate metrics are normalized to a common basis，such as
seconds，they are very useful for comparing relative speeds．For instance，a
vehicle that travels at 50 m/s will obviously traverse more ground in a
fixed time interval than will a vehicle traveling at 35 m/s．<BR><BR>The
MIPS metric is an attempt to develop a rate metric for computer systems
that allows a direct comparison of their speeds．While in the physical
world speed is measured as the distance traveled per unit time，MIPS
defines the computer system’s unit of“distance” as the execution of an
instruction．Thus，MIPS，which is an acronym for millions of instructions
executed per second，is defined to be<BR><BR>（2. 1）<BR><BR>where is the
time required to execute n total
instructions．<BR><BR>3．SPEC<BR><BR><BR><BR>To standardize the definition
of the actual result produced by a computer system
in“typical”usage，several computer manufacturers banded to together to form
the System Performance Evaluation Cooperative（SPEC）．This group identified
a set of integer and floating-point benchmark programs that was intended
to reflect the way most workstation-class computer systems were actually
used．Additionally，and，perhaps，most importantly，they also standardized the
methodology for measuring and reporting the performance obtained when
executing these programs．<BR><BR>4．Benchmark programs<BR><BR>To measure
the maximum speed of an automobile，it must be in motion．Similarly，a
computer must be executing some sort of program when you attempt to
measure any aspect of its performance．Since you are ultimately interested
in how the computer performs[2] on your application programs，the best
program to run is，obviously，one of your own applications.
Unfortunately，this is not always possible since a substantial amount of
time and effort may be required to port your existing application to a new
computer system．It will perhaps not be cost-effective to port the
application if the only goal is to measure the performance of the new
system．<BR><BR>Owing to these practical and logistical difficulties in
running your application program on the system or systems being
evaluated，you instead are often forced to rely on making measurements
while the computer system is executing some other program．This surrogate
program is referred to as a benchmark program since it is used as a
standard reference for comparing performance results．<BR><BR>Since
different application domains have different execution characteristics，a
wide range of benchmark programs has been developed in the attempt to
characterize these different domains．Furthermore，different types of
benchmarks satisfy the needs of many different types of users．Designers of
new computer systems，for instance，often need benchmarks during the early
stages of the design process that are focused on exercising specific
components of the system．Since these early design stages typically rely on
simulations to estimate performance，these benchmarks must be relatively
small and easy to use．A large organization deciding which of several
⌨️ 快捷键说明
复制代码
Ctrl + C
搜索代码
Ctrl + F
全屏模式
F11
切换主题
Ctrl + Shift + D
显示快捷键
?
增大字号
Ctrl + =
减小字号
Ctrl + -