Things to read first
Downloading as fast as your connection allows requires good settings based on the upload speed of your Internet connection. First, fix your NAT problem if you never see the green smiley as torrent health and do not Force Start your torrents. Running another P2P program while Azureus is running will stall your downloads badly as they will fight for the same bandwidth.
The following suggestions should work well most of the time. Downloads of individual torrents also depend on other factors (see Good Torrents).
 Good settings based upload speed
Note: Find your upload speed at next chapter.
If the chart below does not list your upload speed, you might use a calculator page or get new settings using AzBot.
If you are running several file-sharing programs on the same internet connection -- on one or more PCs -- you need to split the upload bandwidth and calculate queue settings accordingly. When in doubt, ask in the IRC channel.
Attention: You need to change the User Proficiency Mode (Mode options) at least to "Intermediate" to be able to change all settings!
|Option||Upload speed of internet connection in kbit/s|
|Upload speed in kbit/s||128 3G(HSDPA)||128||256||512||768||1024||2048||5000|
|Options -> Transfer options|
|kB/s global max. upload speed||6-11||12||25||51||76||100||200||400|
|kB/s global max. download speed||0||0||0||0||0||0||0||0|
|Default max. upload slots per torrent||1-2||2||3||5||6||8||10||15|
|Maximum number of connections per torrent||25||55||60||80||90||100||100||100|
|Maximum number of connections globally||40||80||130||200||250||300||300||360|
|Options -> Queue options|
|max. simultaneous downloads||1||1||2||2||2||3||4||4|
|max. active torrents||1||1||2||2||3||4||6||6|
In any case, do not let Azureus (or any other program for that matter) take up the whole upload bandwidth. There needs to be room for overhead such as acknowledgement signals (ACKs) and resend requests. Downloads will suffer if these signals cannot be sent.
Set your upload limit to about 80% of the maximum possible. Setting your upload too low may result in your torrents downloading slower, so it is about finding a balance between the maximum speed and maintaining a low enough latency for smooth internet usage.
 How to determine your upload speed
To configure Azureus for optimum performance, you need to know the upstream capacity of your Internet connection, which can be obtained from your Internet Service Provider (ISP). Advertisements may include numbers like "1024/256 Kbps"; this represents the maximum bandwidth available to you. It is the number of kilobits per second (kbit/s or Kbps) you can download/upload with your connection. You may have seen speed measured in kiloBytes per second as commonly reported by browsers. There is a difference between the two measures. In all likelihood, you upload slower than you download.
- ISPs and most speedtests use kilobits/megabits, while Vuze uses kiloBytes by default.
- 1 Byte = 8 bits, 1 kB/s = 8 kbit/s = 8 kb/s. Small and capital 'B's do matter.
You may visit http://www.speedtest.net or http://www.dslreports.com/stest or http://www.adslguide.org.uk/tools/speedtest.asp for online speed tests. Stop ALL Internet activity on your machine (including torrents) for a few minutes before running a test. Repeat it twice to reduce number anomalies. If it's close to one of the listed upload speeds, use the chart. Otherwise, use AzBot or a calculator page.
You can always set Options -> Transfer > kB/s global max. upload speed to 0 -- meaning unlimited -- and observe what happens. Most likely it will reach your max. upload speed and then start oscillating, as the too high uploading will cause traffic jams.
 Test real-life torrent speed before complaining
If you get green smileys as torrents' "Health", then you know that your basic network settings are ok. However, that doesn't guarantee speedy transfers.
It is good to understand that
- there is no central server from which you download. Everything that users download, is at the same time uploaded by other users
- you contact other users for your downloads
- respectively, others should be able to contact you (NAT & port forwarding to be configured)
It is quite possible with a "new" torrent or an one with "small" swarm (only a few peers), that the missing pieces are not available. So, it is quite possible that torrent remains active with "downloading" status, but is not actively downloading anything as there is nobody to download from.
Before thinking that your configuration is slow, test it with a "known speedy" torrent. E.g. the following torrent has very high speed: http://releases.ubuntu.com/12.04/ubuntu-12.04-desktop-i386.iso.torrent
It is a Ubuntu Linux distribution, which has lots of seeders, and you should reach your internet connection's maximum speed in most cases (especially with ADSL/cable home connections). Speeds well over 10 Mbit/s (= 1 MB/s as Vuze sees it) should be reachable. You don't have to download the 600 MB torrent completely, but you can use it as a test case for measuring maximum speeds of genuine torrents.
 Other things to know
Read about Good Torrents. (Bad torrents may be fast at first, but you won't finish them.) You may want to compare your download speed with the Average Swarm Speed; you may be doing better than you think.
Read the Azureus FAQ