Torrent Troubles

April 29, 2005 11:40 PM

Why does bitTorrent run SOOOOO slow on my computer?

Perhaps I'm using it wrong, I'm not exactly knowledgeable about the service. However, I have been trying to download files recently using bitTorrent...and I read in WIRED that the beauty of the program is that it will download large files incredibly fast. However, it seems to take hours and hours for files to download when I use it. Has anyone had the same experience and is there something I can do to speed up the download process?

posted by ebeeb to technology (16 comments total)

You need to allow incoming connections, which your firewall or NAT may be preventing. The port number is probably 6881, but that depends on the BitTorrent client and how it is configured.

BitTorrent works by sharing chunks of data between all the peers. The more you're willing to share, the more other peers will be willing to share with you. If you're not allowing incoming connections, you can't share anything at all, and your connection speed will suffer greatly.
posted by nmiell at 11:44 PM on April 29, 2005

Actually you can still share if you're not allowing incoming connections. It's just that you're limited in who you can connect to. Two people, neither of whom allow incoming connections, can never talk to each other. If you allow incoming connections, then you can talk to anyone. Once two people are talking, they can both send and receive. So basically you're just allowing the possibility of communicating with those people who don't realize that _they_ should allow incoming connections.

Another thing you can do is limit your maximum upload rate to about 80% of your upstream bandwidth. If you leave it unlimited, the upstream can get congested, which can slow the downstream as well because there's no room left for protocol overhead.

But a lot of times it's just slow anyway. Most people have much more downstream bandwidth than they do upstream. The limiting factor in your download speed is going to be the average available upstream bandwidth of the other participants. That may be only something like 128kbps - 512kbps, which is a lot slower than most web sites will feed data to you.

Taking several hours to download a file that's hundreds of megabytes or more is not really unusual.

You could also try to wait until more people are "seeding"; that is, have completed the file but are still sharing it. When the torrent is new, the data hasn't been spread around from the original seed yet, so everyone is limited to the original seed's bandwidth. As more people turn into seeds, the download becomes faster and faster, so the transfer itself may take less time if you wait until the torrent is not so new. On the other hand, that could backfire because people who have completed the file tend to drop off after a while. Plus, if you only care when your download is complete, you may not care whether you're connected to the torrent for more of that time or not.
posted by mcguirk at 12:43 AM on April 30, 2005

I had awful trouble with BT with my last provider, arranged by my brother. It turned out they aggresively block, or throttle, ports (the tunnels that the data travels on) that aren't used by web browsers or email. I switched providers and hey presto everything was better, but not great.

Hunting the internet for forums discussing BT and your provider's service might reveal some interesting results.
posted by Navek Rednam at 1:12 AM on April 30, 2005

FAQ

BTW, I regularly download 9GB torrents. Sometimes it takes weeks, especially if you are one of the first like mcguirk said.

The BT client I use utilizes ports 6881-6889, but the client you use may be different (or configurable).
posted by schyler523 at 1:23 AM on April 30, 2005

The speed of a torrent is very dependent on the other people sharing ("leeching") the file. Whenever a torrent is posted to MeFi, I get ridiculous speeds, because the other users continue to share, probably have their clients set up properly, and are perhaps more likely than the average user to be connected to a fiber line, SDSL, etc..

So it has no real speed limit, but no minimum either.
posted by Jack Karaoke at 3:39 AM on April 30, 2005

Downloading the complete Led Zep catalog took me about 4 days. When I get a half hour TV show that I forgot to TiVo, it regularly takes 8 hours. It's a slow process, but for what it is, it's worth it.
posted by abbyladybug at 4:48 AM on April 30, 2005

Ebeeb: what kind of internet connection do you have?

If it's dialup, BitTorrent won't magically make it into broadband.
posted by flabdablet at 5:12 AM on April 30, 2005

I'm amazed at how slow the torrent is. Most people brag about how fast they've downloaded stuff, so it's nice to get a perspective about how long it can actually take. I've gotten episodedes of 30 minute tv shows in 20 minutes before, but that's the exception. Maybe a w.a.s.t.e network with trusted friends would be quicker. Personally, I want a vcr that I can control with my computer and use it as an analog tivo.
posted by mecran01 at 6:05 AM on April 30, 2005

Another thing thing you can do to improve your speed is to try downloading from sites that require membership. These sites track your ratio over time, which encourages people to leave their torrents seeding for longer. The difference between downloading a TV episode from a public site like btefnet and a private site like shuntv is like night and day.

Every morning when I wake up I download the previous night's Daily Show, and it usually takes around 4 or 5 minutes.
posted by llamateur at 7:48 AM on April 30, 2005

Your torrent tracker (whatever site you're using to find torrents) will probably say in your profile whether you are "clever" or "firewalled" (you want to be clever, you do not want to be firewalled). This site will tell you how to configure your router or firewall to let incoming connections through. You'll also need to configure your torrent client to use the same ports that your firewall/router has opened.
posted by mookieproof at 8:06 AM on April 30, 2005

Another handy trouble shooter is this site which will tell you if you are running a NAT or not, some modems have a NAT built into them and might have to configure that. If your running XP you might want to turn off the built in firewall if you haven't already. Here is a link to other firewall/NAT/switch quirks and BT and possible solutions to your problem. If it isn't your firewall or router blocking ports try changing the port numbers within the client your using. Some trackers have changed the default port numbers they use to (usually) the range of 49152 upwards since ISP's like to block default p2p port numbers, this is a attempt to get around that, so the problem just might be with the tracker.

If your using an ISP like Shaw in the Vancouver area (for instance) you'll never be able to go faster, they are limiting BT traffic at the ISP level. I'd check DSL Reports to see if your ISP is one of them.

BT used to go blazingly fast but that was before so many clients had bandwidth limiters in them, the other problem is people don't seed once they get their 1:1, I liked BT more before the universe knew what BT was *sigh*
posted by squeak at 8:41 AM on April 30, 2005

BT used to go blazingly fast but that was before so many clients had bandwidth limiters in them, the other problem is people don't seed once they get their 1:1, I liked BT more before the universe knew what BT was *sigh*

I suppose that's why so many trackers are moving toward registrations and upload/download ratios and things. There are a couple of sites I'd love to use but I don't have an invite etc...
posted by daveirl at 9:47 AM on April 30, 2005

Thanks for all the advice. I'm using a broadband connection and I turned off my firewall before I started using BT, so I'm going to mess around with some of my settings as suggested and see what I can do. It seems as if I am going to have to get used to it taking a while for downloads...but I agree that it's worth it for what it is. (Also: good looks on the membership site suggestions!)
posted by ebeeb at 7:15 AM on May 1, 2005

There's no magic behind bittorrent. If you're downloading a single file from a single source that can only send you the file at 5 kbps, you're going to have to wait no matter what protocol you use (FTP, HTTP, etc.)

With bittorrent, if 10 people are all offering the same file at 5 kbps., you can (theoretically) have a 50 kbps download. Alternatively, if 5 people have the entire file, but another 5 people only have half the file, you can still download at 50 kbps (at least, the first half of the file). That is the power of bittorrent.

Maybe a w.a.s.t.e network with trusted friends would be quicker

Unlikely, unless all your trusted friends already have the file. If you're all just downloading from one person, you: 1. Must make sure everyone keeps their clients open (this is why ratio sites are good) and 2. The first person seeding the file must use SuperSeed.

SuperSeeding works something like this: Let's say I've just encoded a new episode of Dr. Who, and I want to share it with the world. OK, so I post it up on a public tracker, and BLAMMO!, 500 people are trying to download it at the same time. My bittorrent client tries establishing 500 connections and gets completely swamped. Normally, clients are configured to stop at about 30 connections, but even this would take forever. What I need to do is SuperSeed the file.

In this situation, the client picks just a couple of the 500 people with the fastest connection/lowest ping time and gives it directly to that person. Those people are connected to their regular 30 peers, who in effect trickle-down the file to everyone else. This takes the strain off the original seeder, who can then seed it at maximum throughput, and makes everyone else get the file faster.

Also, it's important to use a good BitTorrent client. I used to use Azureus exclusively, then realized that the Java VM was sucking up enormous amounts of memory. I switched to BitComet, just because it gives me nearly the same functionality, yet is compiled to be used on Windows systems. As much as I loved Azureus, it was no match for a natively-compiled/executed client like BitComet. /$0.02
posted by Civil_Disobedient at 12:55 PM on May 1, 2005

There is a small possibility that your network card is having trouble with bittorrent. For example, the Netgear GA-302T gigabit cards crawl along for a little while, then hard crash. After that, they require the machine to be rebooted before the nic will function at all again. Apparently, this has something to do with the large number of connections that bittorrent transfers make.
posted by Caviar at 9:01 PM on May 1, 2005

BitTorrent's speed is often misportrayed in articles on it. BitTorrent is always going to be slower than downloading a file from a fast central server that isn't overloaded. It's typically going to be faster than other P2P clients, where a lot of what you're downloading might come from people with slow connections (and you're stuck with that slow connection for the whole download.)

Where BitTorrent shines is for large downloads with bursty demand, like a just-released Linux distro. 'cause though any individual would have gotten the file faster from a fast server that wasn't overloaded, they're all overloaded. BitTorrent means that a much larger number of people can get the whole file during the large burst of demand.

So it's faster in terms of time to deliver a large number of total person-downloads during high demand, not faster in terms of one individual getting a file (if that individual had access to a server that's not overloaded.)

And what Civil_Disobedient said.
posted by Zed_Lopez at 10:48 AM on May 2, 2005