Reasons for slow download rates
Computers are never fast enough! You will see some downloads happening much faster than others. Here are some reasons why downloads might be slow:
- You are starting up. Because of the way BitTorrent works, you might see an encouraging surge of download activity followed by a quiet period before the download gets going again. That’s normal.
- You are at the end of the download – known as the ‘end game’. At this point you need a few specific pieces – no others will do. You can ask only people that have those pieces which restricts your downloading options. If the people the client picks do not provide the data for some reason or provide it very slowly, you will see poor download rates.
- Your BitTorrent port is not open. This means people cannot contact you directly. You are restricted to connections you initiate. If your port is not open you will see poor download rates. See here for help setting up your port and here for help with testing your port.
- Your ISP is interfering with your BitTorrent connection. Most are coy about what they do if they detect what they regard as bad behaviour. For some, use of BitTorrent is evidence of bad behaviour. If you start seeing slow download speeds it might be because your connection is being throttled or your BitTorrent port is being blocked. Try testing your BitTorrent port again. If it worked before and it is not working now, try using the green Tuning button in the BitTorrent client to switch to a different port number. When possible, try running downloads late at night or during the day. Downloading at peak times often results in throttling. Also, check your useage conditions; you might be using a connection that has a limited download capacity that you have exceeded.
- A small swarm. If you have just a few people to deal with download rates will suffer. In a larger swarm, the client can ignore people that will not download to you and move on. That’s not possible in a small swarm. It’s not certain, however, that a small swarm will yield poor download rates. If one member of the swarm has a high upload rate, there’s a better chance you will benefit from it.
- Many more leechers than seeders. Most people have a much slower upload rate than download rate. That’s a by-product of ADSL technology. As a result, the more leechers in a swarm, the more people are competing for the limited upload capacity available. It is particularly difficult to get started in a swarm with lots of leechers because, if you have very little data, you are not attractive to peers that will prefer to deal with people that have a better chance of providing the data they need. You will often get better download speeds for a popular torrent if you wait a while until the number of seeders has increased relative to the number of leechers.
- Contention on your Internet connection. Any other activity on your Internet connection has the potential to slow down your download. That could be from other programs on your PC or from other PCs that share your Internet connection.
- What you are downloading. I have noticed that download rates tend to be better if they are attractive to ‘geeks’, for example. I think that’s because they tend to have better computer equipment than most and are more likely to have opened their BitTorrent ports to the Internet.
- Bad luck. When you connect to a swarm, the Tracker allocates a few people from the swarm for you to contact. If, for example, none of those people have an open port, you will be unable to connect with any of them and you will not get any data. It’s almost as bad if everyone has poor upload capacity. The download rate you get at any time – especially in large swarms – is mainly down to luck.
If you see poor download rates, have patience. The client is designed to automatically improve the rate over time. It is very common for a period of poor download rate to be followed by a period of high download rate.
If the client sees consistently poor download rates it will try to resucitate the torrent by restarting it.