标题: Firefox 3真实的内存使用 [打印本页]

---

作者: Mallon    时间: 2008-6-25 17:58     标题: Firefox 3真实的内存使用

http://software.solidot.org/software/08/06/25/0548258.shtml

一位程序员为Windows操作系统开发了一款每3秒记录一次浏览器内存使用的程序，他记录了5种浏览器在3小时内的内存使用数据点：Safari3.1，Firefox 3，Flock 1.2（基于Firefox 2的浏览器), Opera 9.5，和Internet Explorer8，都没有使用扩展程序。约1百万的数据点显示Firefox 3在内存使用上确实比其它浏览器有不小的优势。作者认为：Safari 3.1（Windows）的内存管理很糟糕，Opera 9.5的新内核Kestrel并不能称得上是革命性的技术。

---

作者: Mallon    时间: 2008-6-25 17:59

Firefox 3 Memory Benchmarks and Comparison

by Sam Allen

Web browser performance is an often talked-about and flaunted thing, but many claimsare not really backed up by solid evidence. I wrote software that collected millionsof data points over 14 hours of actual browsing time, and this article revealsmy findings.

ProblemMany people load hundreds of web pages, sometimes at the same time, oftenover periods of 3+ hours. Users complain about the memory usage of Firefox, Safari,or Internet Explorer, and we need a way to identify which browsers are better atmanaging memory than others. Traditional benchmarks do not look at all the thingsyou might do with a program, and we need real-world numbers over a period of hours.

SolutionI developed a Windows Forms application in .NET called Memory Watcher that "watches"the system memory numbers. It uses a timer to poll the processes every 3 seconds.It then records every number and also prints them out in a grid on the screen. Thisallows us to keep track of each program's memory usage over time and with real-worldusage.

Memory ProfilesThese results are from opening Memory Watcher and then using the browser between9,000 and 11,000 seconds (close to 3 hours). Each browser is tested in a separatesession, and there are brief periods of inactivity throughout the time period.The vertical axis is the memory used in MB, and the horizontal axis contains thememory "checkpoints" my program took (one every 3 seconds).



Benchmark DetailsThe above profiles are not a direct comparison in any way, but they offer a visualizationof trending in the memory behavior of the layout engines and interfaces.This is not a diagnosis or bug report. Let me show some important metrics of theabove results.

Browser name	Exact version	Time active (s) Hours	Comments
Safari	3.1.2	10,470 s 2.91 hours	Normal browsing
Firefox	3.0	9,681 s 2.69 hours	Normal browsing No extensions
Flock	1.2.2	10,146 s 2.82 hours	Flock is based on Firefox 2.0 No extensions other than the default
Opera	9.5	9,855 s 2.74 hours	No extensions Only browser was used
IE	8.0	10,236 s 2.84 hours	Used 7.0 rendering mode No extensions

The system is Windows Vista SP1, and the computer has 3.0+ GB of RAM. No pluginsare disabled, but the Acrobat Reader and Java plugins were (presumably) not used.Flock is based on Firefox 2.0 but its memory usage is probably worse because ituses built-in extensions.

• Just regular stuff
  These aren't stress tests, and I probably never went over 4 windows in each browser,with at most 3 tabs in each window. I didn't look at many pages that are extremelyheavy on images, and no "browser benchmark" style pages. Gmail was used on eachbrowser.
• Not just pages
  It is hard for a regular benchmark to "simulate" a user actually clicking on things.Interactions with the user can greatly influence memory or performance. Having aresponsive browser is probably more important than just having a "fast" one at showingpages.
• Plugins included
  My profiles include Flash and possibly other plugins. A browser might have memoryissues with a plugin and that could cause a significant problem with the user experience.(Most Windows Vista crashes have been due to graphics cards, not Vista itself, forexample.)
• Real-life usage
  An automation script will never give the same insight into performance over timeas will this sort of profile. As developers, we want to make programs that workwell for our users, and not just for tests. The tests capture the "rhythm" of softwareusage.

Final Memory MeasurementsThe data in this article are those reported by Windows Vista, but the individualnumbers should not be compared to each other. Some browsers were tested slightlylonger than others, and some different pages were loaded. That said, here are thefinal performance metrics.

Browser name	Ending private set in MB
Safari	636.9
Firefox 3	111.8
Flock (Firefox 2)	191.9
Opera 9.5	190.6
Internet Explorer	194.4

About the "Memory Watcher"Memory Watcher is a small program I wrote that records the memory usage of eachprocess on the system every three seconds. It uses the PrivateMemorySize64long value from the Process collection in .NET.

• Simple
  There are tools similar to this, offered on every platform, but they are not usuallyeasy to use. Memory Watcher provides a super-easy way to monitor every process andsilently work in the background.
• Exports to spreadsheet
  It exports the currently viewed data to a CSV file. These data are easily taken into Excel, and were used for the graphs in this article.
• Implementation notes
  The application uses a DataGridView control,and sets its DataSource property to aDataTable which is built from the objectcollection. It uses a Timer to poll the system every 3 seconds. It offers searchingand filtering of processes using a TextBox.

ConclusionThese profiles are meant to provide a picture of what the memory behavior of popularbrowsers is over a period of time, not to provide absolute benchmark times. Firefox3.0 shows memory usage that is significantly lower than Firefox 2, which also doesvery well. Here is a summary of my results.

• Safari 3.1
  Safari on Windows shows extremely poor memory management, and I do not know whetherit ever reaches a high water mark. If this is by design, it is certainly a designthat looks inefficient and seems to contradict Apple's marketing.
• Firefox 3.0
  This browser exhibits memory usage that is by far lower than the others. It releasesmemory to the system and the trend line is nearly flat.
  (This is likely due to the efforts outlined here.)
• Flock (based on Firefox 2.0)
  Flock did very well and this browser and Firefox 2.0 could likely be run for longperiods without causing many problems. The extensions probably reduced the efficiencysomewhat.
• Opera 9.5
  Opera's performance was about as good as Firefox 2.0 (Flock), and it could likelybe used for very lengthy sessions. However, Kestrel is certainly not a revolutionaryor even notable technology in this arena.
• Internet Explorer 8 Beta 1
  IE did well in the profile, although a worrying trend in the data could indicatethat it would keep escalating. However, this browser could likely sustain many hoursof moderate usage.

Final ThoughtsAfter browsing for 14 hours with these programs, and recording all the results intospreadsheets, the most memory efficient browser in my usage is very clear--Firefox3.0 not only trumps its older version, but every other popular offering on Windows.This article may help other vendors rethink their marketing campaigns, and may promptfurther improvements.

[ 本帖最后由 Mallon 于 2008-6-25 18:01 编辑 ]

---

作者: Snowpine    时间: 2008-6-25 23:08

没有感觉特别省内存，但是感觉maxthon特别耗内存，还经常死掉！

---

欢迎光临 幽游生活 (http://www.yylive.net/)

Powered by Discuz! 7.2