the forums at degreez.net

By what fact is you download rate proportional to your upload rate?

no

It is i just dont know the equation. Shadow coded it so I believe hes the man to ask.

Each client in a swarm has a target "number of connections". Each client will try to get the best download out of each connection they have open - every 10 seconds they try connecting to a new peer at random to try to find a better download speed, and if they do they'll stop uploading on the connection with the worst download speed (to keep their target number of connections). Since peers will only upload if they're downloading, if you want a good download speed you need to be able to offer a good upload speed.

Most people have asymmetrical connections. Their top upload speed is a fraction of the download speed and there is nothing that can be done about it.Thus it is difficult to offer great upload speed.