各个浏览器并发连接数比较

The HTTP/1.1 RFC

Section 8.1.4 of the HTTP/1.1 RFC says a “single-user client SHOULD NOT maintain more than 2 connections with any server or proxy.” The key here is the word “should.” Web clients don’t have to follow this guideline. IE8 isn’t the first to exceed this guideline. Opera and Safari hold that honor supporting 4 connections per server.

8.1.4节提到单用户客户端不能维护超过2个连接对任何一个服务器或代理。这里的关键词：“应该”，很多浏览器的实现不严格遵从这个规定，IE8不是第一个超越此标准，Opera Saari已经支持超过4个并发连接。

Settings for Current Browsers

The table below shows the number of connections per server supported by current browsers for HTTP/1.1 as well as HTTP/1.0.

Browser	HTTP/1.1	HTTP/1.0
IE 8	6	?1
IE 6,7	2	4
Firefox 3	22	?1
Firefox 1.5, 2	2	8
Opera 9	4	?1
Safari 3	4	?1

下面一个测试并发速度的页面:

http://stevesouders.com/hpws/parallel-downloads.php

一般而言，浏览器所支持对同一Server的并发数越多多好，IE8应该不错。

我本机IE7：

Page load time:

5203 ms

本机FF2:  

Page load time:    10891 ms 

怎么都是2个并发，差异会这么大，哈哈，用的IE还是较多一些。