Hi,
I am using emule v.30c and am experimenting with the various settings in order to try and get consistently good download speeds (e.g. setting to "Release" those files you want most, choosing which server to connect to, etc.)
My question is this: Obviously unless you are downloading anything else, you would want to set your max download speed to the highest your connection will allow (not that you will always get that much). But why would anyoone set their max upload speed to anything less than what the connection will allow? Surely you build up credits quicker if your upload speed is higher. And if, as far as I can tell, your upload speed doesn't affect how quick you can download, why would you want to set it to 80% or whatever?
My connection is 256/128 so I have set my max levels to 32/16. Should they be any different?
Upload does affect downloads. And anyway, you should have set download speed to 0. It works for me (in some aspects considering how ****ing crap my connection is), and it might work for you.
It is true that it is a very good idea to leave a little bit of upload bandwith available; 20% is typically adequate. This is because saturating the upstream does affect the downstream. In fact, any amount of uploading affects the downstream to some extent. The reason it affects download speeds simply comes down to how the tcp/ip protocol works. When you are downloading, you are also uploading what are called acknowledgement packets, a.k.a. ACK packets, to the server you are downloading from. That is to say, after a predefined amount of data is sent to you, your machine must acknowledge to the server that it has received the last window of data before any more data will be sent. (The term server is used loosely here, regardless of where/what you download, the protocol remains the same.) What tends to happen when you don't leave enough upstream bandwith is that the ACK packets, being very low-priority packets (ICMP) by their very nature, must wait for an open slot in the upstream; so the closer you are to saturating your upstream with higher priority packets, the longer the ACK must wait, and in turn, your download must wait. You can observe this phenomenon for yourself by downloading a quality ftp test with and without saturating your upstream to varying degrees with eMule. You can find some speed tests to use and other information about tcp/ip protocol and upstream saturation at http://www.dslreports.com . Then you can basically decide for yourself by experimenting how much upstream you need free to surf the web and run other applications. Hope this helps!
