i'm a newbie to torrent, so i'm not responsible to anything i wrote here.
correct me if i'm wrong, as i understand, during download we are constantly searching and requesting data amongst the peers and seeders.
say u found this guy who owns a chunk u like, and he in turns also interested in your chunk of data. so obviously u want to trade with him, in a tit-for-tat scheme. u give me some i give u some.
say there are another 50 guys out there who also found him, are also interested in his chunk, and each of them has their own chunk he likes to trade.
since he can only trade with say, 10 guys, who do u think he will choose?
yep, rightly he will prefer those who can send him (trade with him) the fastest. meaning those with the highest upload speed.
so limiting your upload decreases your chances of securing a connection to download data. and those with already low transfer rate would suffer more of being ignored when entering a swarm full of high speed connections. not even the optimistic unchocking algorithm can help much.
to add some more salt, the seeders who only doing upload will prefer those with the fastest download rate and will forever connect to them.
