Why would certain torrent trackers not let me upload?

Question

When I download torrents from certain trackers (usually ones with set ratio limits), I can't seem to upload much, even when download is blazingly fast. On other trackers (sadly - the ones with no ratio), after I finish downloading (and even while downloading), I manage to get up to 30KB/s upload, and pass 1.0 ratio in no time.
Why would this happen? Am I throtelled back by some trackers for some reason?

Answer 1

On trackers with ratio limits, users are usually more keen on keeping their ratio high, so they download new files as fast as possible upon release so they can be one of the first users seeding and raise their ratio more. Then regular users like yourself download the file and have trouble seeding. This is because most of the users already have the file downloaded, and the ones that are downloading have plenty of seeds, so each seeder will only need to contribute a smaller upload speed. The tracker is not throttling you whatsoever though, just jump on new torrents faster!

Answer 2

Many people on private trackers also have servers that are seeding for them. Usually in the 100mbit to 1gbit speed range. Pair this up with automatic download scripts (Not RSS, which gets polled every few minutes, but something like an IRC announce parser script), and you have dedicated servers with 100mbit or 1gbit connections that are downloading new releases near instantly as soon as they are on the tracker. This makes it virtually impossible for normal home leechers to attain a 1.0 ratio on said torrent, but it is possible, if you have the space to accommodate all of the files that were downloaded, the bandwidth to continue seeding, and the patience to wait.

Also take into consideration that a private tracker has a smaller userbase than a public tracker. If you download a torrent, it's not as likely that the other members will also download that same torrent compared to a public tracker where the chances are increased.

This is why those types of trackers are better geared for people with servers or fast connections, as those without them aren't likely to 'survive' in that environment which enforces minimum ratio requirements.

Keep in mind though, not all private trackers are like this, but a good chunk of them are (Unfortunately for many, usually the ones worth being a part of).