4/10/2007
BT的速度越来越不能令人满意,以前喜欢的Bitcomet的内核越做越低效,广告倒是多了不少,自己修改也不再有意义,于是投奔了老外的uTorrent,没有料到收获的不仅仅是一个资源占用小而速度高效的客户端。
重新选择了bt客户端,了解一下设置,在uTorrent的网站的FAQ和Sticky里面好好浏览了一下有关的Guide。无意中看到那段"TCPIP.SYS should be patched and you should never set it higher than 50! net.max_halfopen should ALWAYS be set lower than the value you patched tcpip.sys to" 这话题其实以前自己在国内的几个论坛,包括学校的论坛有过讨论,就是TCP连接数问题,没有半点收获,现在索性开个新帖,和老外交流下。
在作者的解释下搞明白:Global maximum number of connections is not the same as halfopen connections. Halfopen connections are like you making a phone call, but it hasn't been picked up on the other end. net.max_halfopen limits the number of those you can make at any given time, but does not limit how many fully-established connections (phone calls that are successfully picked up from the other end) you can make. net.max_halfopen is supposed to be 8 by default, and the global maximum number of connections is irrelevant to it.The TCPIP.sys limit is only a half-open connection limit, so again, it doesn't affect fully-open connections, or how many can be established.
至此明白了连接数的作用,搞清了以前蝙蝠说的不修改也不影响的原因,也知道了如何在BT中设置才是对速度有益。TCP连接数用lvlord的补丁设置(http://www.lvllord.de/),设50是够用了,过多的连接数只能耗费系统资源,半开连接数并没有想象中有那么强烈的依赖性,在一段连接时期后甚至只是保留个位数就足够,因此成百上千的设法并不足取。