Why setting a ratio of 2 in Transmission doesn't restrict the upload speed to 2 times the download speed?

In the Transmission application, I assumed you select a torrent and then select Properties → Options and there exists a Ratio option. If you go into the Seeding Limits settings, I thought if I set it to Stop seeding at ratio and use their default value of 2, that it would stop uploading when the speed got to 2 times the download.

But this seems to have no effect at all. The torrent will still get downloaded at less than 100 kbps but get uploaded at 660+ kbps. I consider it good etiquette to upload while downloading, but would like it to be more balanced. If I'm uploading at 600+ kbps, I don't like to be downloading at less than 100 kbps.

Is there some way to download a torrent at an even rate?

You seem to be confused about what the Stop seeding at ratio option means. It doesn't alter the upload/download speeds to a ratio of 2 (the default value and what you used), meaning for example that if your download speed is 100 kbps your upload speed will be 200 kbps.

What this option really does is that, after the download of your torrent is completed, it will stop seeding it (uploading) when you have uploaded twice (for the default value of 2) the amount you downloaded. For example, if you have downloaded a 1.5 GB file, Transmission will stop uploading it when you have uploaded 3 GB.

What you actually want to do is to set limits for the download and upload speeds. To do that, select your torrent, go to Properties → Options tab → check Limit download speed (kB/s) and Limit upload speed (kB/s) under Speed and set the values you desire as your download and upload limits:

Note that the above procedure will set the speed limits for the specific torrent only. If you want to set speed limits globally (for all torrents), you can go to Edit → Preferences → Speed tab → check Upload (kB/s) and Upload (kB/s) under Speed Limits and set the values you desire as your download and upload limits:

I believe you've misinterpreted what ratio means. From Wikipedia:

A user's share ratio for any individual torrent is a number determined by dividing the amount of data that user has uploaded by the amount of data they have downloaded. Final share ratios over 1.0 carry a positive connotation in the BitTorrent community, because they indicate that the user has sent more data to other users than they received. Likewise, share ratios under 1 have negative connotation.

So the ratio has nothing to do with upload/download speed, but instead it affects the total amount uploaded, compared to the total size of the torrent.

So if you have a ratio of 2, and download a 1 GB torrent, the upload will stop after having uploaded 2 GB.

If you have installed the transmission-remote utility, you can have access to the same options as the desktop app by using the command line.

• If you're using Ubuntu Server, the remote capabilities of Transmission are enabled by default
• If you're using Ubuntu Desktop you have to enable them first by going to: Edit → Preferences → Remote tab → check Allow remote access (by default the Transmission server runs on localhost (127.0.0.1) and on port 9091:

The relevant commands to your case are below:

• You can see the current session information (including seed ratio, upload/download speeds etc.) with the command:

  transmission-remote 127.0.0.1:9091 -si
  

For the following commands, if they're run on no specific torrent (no -t parameter), they set the global values.

• You can set the ratio with:

  transmission-remote 127.0.0.1:9091 -sr <ratio>
  

  And to remove the current seed ratio, run this:

  transmission-remote 127.0.0.1:9091 -SR
  

• To set upload or download limit (in kB/s), use these commands.

  Set download limit:

  transmission-remote 127.0.0.1:9091 -d <limit>
  

  Set upload limit:

  transmission-remote 127.0.0.1:9091 -u <limit>
  

For more information about the transmission-remote utility, please see its man pages.