Bittorrent speeds

Kilarney

What's the deal with Bittorrent speeds?
I have a DSL connection with a max of 3.0 Mbps down. I regularly get 2.5 Mbps when I speed test my connection. My upload speed is a maximum of 768 Kbps. I also use a wireless router at home.

I understand that my download speeds are limited by my upload speeds, which is one of the bummers of a DSL line. But how does Bittorrent really figure out your download speed? All I keep hearing is that there is some sort of "algorithm."

I typically download at about 35 kB/s. Upload speeds are about half that. Every now and then, I'll download something at 250 kB/s or faster. So obviously the potential is there for fast downloads - I just reach those speeds very rarely.

I always have other torrents that are in demand for upload. I always wait until my upload/download ratio is higher than 1.0 for each file that I have downloaded before I turn off Utorrent.

So what gives? Why are my downloads so slow? Are these speeds normal, or is there a fix for higher speeds? Could it be that my router is giving me trouble? Just what exactly is important as for as the "algorithm" is concerned? I'd really appreciate it if anyone has some ideas. Thanks!

thaneofcawdor

The most important factor, in my experience, is the ratio of seeders to leechers. Seeders are users with the whole file who are just uploading, and leeches are people both downloading and sharing what they have. Unless the ratio of seeders to leechers is about 2:1 or better, I don't bother, because the download is never as fast as my connection can allow.

Apreche

We're going to do an episode on how bittorrent works and such. In the meantime you can read this.

Kilarney

The most important factor, in my experience, is the ratio of seeders to leechers.

That makes sense. The file I'm downloading now has 7 leechers for every seed, and it's chugging along at about 30 kBps.

Kilarney

I just turned on encryption, and my speed pretty much doubled. If this is true over time, it looks like Verizon was throttling.

UPDATE: The speeds have fallen down to their normal levels again. It appears as though I was just seeing a normal fluctuation.

UPDATE #2: Speeds are back up again. Looks like I'll have to watch this one over time to see if there is anything to it.

HMTKSteve

What's a good client to use with encryption?

Kilarney

Some more research indicates that Verizon does not throttle torrent downloads. Back to the drawing board!

UTorrent has encryption built in. It is a deal they have with Azareus to fool ISPs that throttle torrents. You just have to select encryption from the options menu.

Kilarney

I've spent three hours or so tweaking Utorrent. After all of that, the download speed stayed about 30kB/s. Interestingly enough, when I allowed two downloads at the same time, they both had a download speed of about 30kB/s for a total of 60kB/s. I suspect, therefore, it has more to do with the fact that I am downloading seeds that have a ton of leechers. At least I'm now downloading twice as fast if I have more than one item in the queue.

I did realize that my upload speed was set way too slow. Hopefully that will improve things in the future.

techsupportrich

So much depends on the people you are downloading from. It doesn't really matter if you have 50 connections if they're all using dial up. My own bit torrent experiences have seen speeds up to around 520kbps but that is quite rare, more usually around 300 for the more requested files. A good test is to download a Linux distro over bit torrent. People who use Linux tend to have high end internet connections.

Kilarney

I'm averaging about double my upload speed, which I have read is really as much as you can expect. Darn DSL!

navelfluff

Looking at the way my bittorrent uploads/downloads work, I have problems believing that there is an algorithm controlling my download speed. Sometimes a download uses my whole 5Mbps download bandwidth and is done in a flash (well, almost). I guess that means that I for a while am lucky to be one of few people downloading from seeders with very high upload speed. It's rare, but it happens. Most of the time my download speed sucks.

I guess most bittorrent users have asymmetric DSL, which means that the amount of collective upload speed is usually 1/2-1/4 of the collective download speed unless there are many seeders who don't download much. Add in a bunch of people with slow dial-up connections, and downloads slow down even further. The download demand is usually much larger than the upload speeds can deliver, which means that people like me me with high bandwidth will use their upload speed at max most of the time, while download speed is still restricted by the slow uploads of other leeches.

It's a bit frustrating that I end up uploading twice as much as I download, but I guess that's the way it has to be until fast, symmetric Internet connections become the norm. Anyway, I feel good about contributing to the community.

spiritfiend

According to theory, a leecher is also feeding you parts of the file that they already have. The only bottleneck is the upload speed of each client you are connected to and the amount of the file that they have received from the group. The latter is a problem when there is only one seeder with crappy upstream bandwidth, and the former is a problem when bandwidth among the clients is capped either by the individual or ISP.

Another problem is the fact that many people running bittorrent through routers have not configured port forwarding properly, so it doesn't allow remote clients to connect to them. This limits the number of people in your group and will affect your download speed. I would recommend running bittorrent off of a non-standard port since ISPs like to throttle it.

tuttle88

Look you're all forgetting something very important. The internet is not a dump truck, it is a series of tubes. And you're speed depends on how much stuff is trying to get through all these tubes.

HMTKSteve

Would those be fallopian tubes?

Furtive

It's a bit frustrating that I end up uploading twice as much as I download...

How come thats frustrating? Bittorrent relies on the community to get files around. I have my client set to share full speed until it reaches a 3.0 share ratio. Everyone of those seeds you're trying to download from are probably people letting their clients run past the 1.0 ratio too. Share the love man.

navelfluff

How come thats frustrating?

I'm happy to share, and at the moment my share ratios are about 2-5.

It is a little bit frustrating, or maybe annoying is a better word. My frustrations are mostly caused by my economical situation. I pay quite a lot for good bandwidth (5Mbps down, 1Mbps up), more than I really can afford as a poor student (but it costs only a little bit more than half the speed, so what do you do?). Then it is bit annoying that the BT client rarely feeds me more than 500kbps from the costly download capacity, while other people benefit from my 1Mbps upload speed at maximum capacity most of the time.

Kilarney

I've come to the conclusion that it really does depend on the seeders and number of leechers. My system is capable of very fast downloads (now that I've tweaked it), but I rarely see those speeds. I usually settle in at 30-75 kB/s, with 30-55 being the norm. I have had much faster downloads, but it is rare.

I've decided that Bittorrent has its advantages, but in day-to-day use it is a fairly slow method of transferring files. It's also frustrating to have to jump on a seed before it goes away. I'll continue to use it, but it's not the answer to my prayers.

For anime, I'd really like to switch over to Usenet, but that's got it's own problems. Let's face it, Usenet wasn't designed for 250mb video files. (Call me lazy, but I hate having to use "rar" compression, etc.) Usenet also has the same problem of having to jump on files when you can.

Rym

Bittorrent is designed specifically to handle swarm downloads. If several hundred people all try to download the same file suddenly, it handles that wonderfully. If only a few people try, you're really no better off with it than without. It's not a filesharing network so much as a flash-download service.

Apreche

Another thing you have to realize about bittorrent, it usually matters more who the seeders and leechers are than how many of them are out there. It's just that statistically speaking if there are lots of seeders and leechers, some of them are going to be really good. Let's say there's a torrent of a file and 100 people get on it. 10 of them finish and start seeding. All of them are in China on dial-up. That won't be a fast download if you join in even though there are plenty of people doing it. Granted, it will be faster than from just one guy on dial-up, but still not fast enough. Now let's say there's a torrent with one seed. That seed is your next door neighbor who has the same ISP. It's going to be wicked fast.

I think in order to appreciate the real power of bittorrent you had to have been downloading popular files five years ago. Let me give you an example. Five years ago Counter-Strike was stupid popular. Whenever an update to the game was released everyone would try to download it at once. We're talking about thousands of people trying to download a file from one server. Eventually they added many mirror servers. So now instead of one server trying to serve a file to 20,000 people at once, you had 20 servers each serving to 1,000 people at once. The servers still couldn't handle the load. Sure, once you started downloading it was fast, but you were lucky if you were able to connect to a mirror on day 2 or 3. Heck, you were lucky if every mirror didn't crash under the intense load. Not only that, but the people providing the downloads had enormous bandwidth bills.

That is the problem that Bittorrent solves. Bittorrent solves the problem when a very large number of people all want one file at the same time. It makes it possible for everyone to get the file without having to go hunting for mirrors. It makes it so nobody has an incredibly large bandwidth bill. it makes it so you don't have to keep returning to the website to try and try again day after day until there is an open FTP slot. Bittorrent is a godsend. But until you understand the problems we used to have, you won't realize just how amazing it is.

The thing is too many people try to view, and use, bittorrent as a replacement for Napster. Yes, bittorrent is technically a p2p file sharing application, but a Napster replacement it is not. If you want to use bittorrent efficiently you can't really go around searching for whatever you want and hopefully find a torrent out there. You have to watch the torrent sites to see what is hot right now, and go for it. This is why it is so perfect for anime fansubs. New episodes are released, everyone gets them, then they slowly dissapear as they are licensed.