Ratio - Upload / Download

[Zeerover]

Does anyone know definitely (as opposed to urban legend) whether your download speed is affected by your "Upload / Download" ratio either by client software or tracker, or by individual torrents or total throughput?

It doesn't make sense to me that anyone would actually be trying to implement that type of throttling since there are a lot of good reasons to not seed a torrent.

- You find that a torrent is of poor quality and don't think it's worth seeding.

- You run out of hard drive space and move a torrent's data files to another computer or hard drive and can't figure out how to tell your client where it went.

- You prefer to select a low upload speed on a particular torrent while it's downloading because you are seeding other torrents that are more important. Perhaps the one you're downloading has 100 seeds and the one your seeding has no other.

- You want to see it before you decide to seed it.

I've been experimenting with utorrent for a few weeks now and can't say I've seen any affect of ratio upon download speed, and can't see how it could be implemented without putting undue restraints upon the user. As soon as a user saw they were being penalized, they'd investigate the source and fix the problem, whether it be the client or tracker, even perhaps seeding their own torrents in a manner that couldn't be penalized.

A torrent should survive because it's popular, not because people feel impelled to perpetuate some piece of garbage. Statistics such as ratio reflect the health and popularity of a torrent. As analogy, a baseball player doesn't hit or catch a ball in order to change his statistics.

So what gives? Are poor ratio's really penalized and good ones rewarded? Or is it urban legend. Do torrent client software developers and trackers really design their product with a priority of herding dipshits that don't seed? I speculate that they don't.

Let's hear what you have to say.

[Ultima]

No one said that you get throttled by your ratio. While BitTorrent isn't really a tit-for-tat system, it clients still "reward" (prefer) other clients that upload to them.

[Switeck]

And you can be uploading at 100 KB/sec and not getting much in return if you're running 50 torrents at once with 20 upload slots each. ...because from each person's point of view that you're uploading to, your upload speed to them (their download speed) is only 0.1 KB/sec. You'll probably still get 20-200 KB/sec download speeds -- but that'd only be due to good torrents (which if you have 50 no doubt SOME will be good).

In a closed torrent, the total DOWNLOAD speed of the whole is always equal OR LESS (due to hashfails and duplicate data) than the total UPLOAD speed of all participants. If someone uploads less, they may not suffer themselves...but it does reduce the max for everyone. If you're downloading faster than you're uploading, someone else isn't...possibly a LOT of people aren't! (Note: They may just be seeders. But even seeders may want to download something else and not just give their upload away indefinitely.)

[Zeerover]

Thanks for the replies. Reading around the net, I got the impression that clients & trackers try to reward or penalize you. There's even pages on how to cheat - get around the penalty or alter your ratio to obtain a reward.

So I think you are agreeing with me that there is no algorithym in a client, at least in utorrent, that looks at your ratio to decide to give you more or less download bandwidth. There are apparently some tracker sites that try to reward you for seeding a lot (and apparently penalize the others in a swarm to do it). However, I don't quite see how they hope to make that work either.

The bottom line seems to be that, if you want the bittorrent network to be a success, you should do your best to seed your share or more in the Total Uploaded/Downloaded Statistics but not worry about a particular torrent. In a particular torrent, you do whatever seems advisable to get the best download rate and that may include increasing your upload rate on that torrent since giving more blocks out to other peers just naturally frees up other peers to give more to you.

Thanks again for the replies.

[Harry Poppins]

What you heared about this penalty thing, was probably related to private trackers. Private trackers don't tolerate a low ratio, and will eventually kick you out if you don't improve it (I'm talking about your overall ratio, not the ratio for one particular torrent). But even in this case, the tracker does not control how fast you download, the only penalty is that you get kicked out (meaning that your username and password is revoked and you can't log in to their website or use any torrent with their tracker).

[alacrity]

When I was new bee, I found a torrent in the newsgroups from a private site. They let me download without creating an account. They advertised they were reseeding every other day, so I usually reseeded only 25%. After a few days I found my download rate to be in single digits instead of triple and my upload was maxed. So I started to force 100% reseed. My download returned to triple digits.

Once I find a download to be crap, I cut it off and report it in a forum if available. When I find something really good, I will reseed for weeks.

[Lord Alderaan]

Private trackers can penalize you by not allowing you to download certain torrents or kick/ban you from the community and/or tracker. AFAIK they cannot influence the speed you get because that is worked out on a connection basis by each client itself.

I'm not knowledgeable of the torrent protocol but I don't think there is a mechanism in it that allows trackers to determine client speed. So its probably some kind of trick or the speed effects alacrity (for example) experienced where due to a normal torrent mechanism and had nothing to do with the tracker. My bet is on the latter.