Upload speeds tied to download cap?

[cwm9]

Lately I've been trying to cap my download speeds without capping my upload speeds, but this does not seem to work properly.

I have set an upload bandwidth cap of 25KB/s.

Normally, with the download cap of a file set to 0 (unlimited), the entire upload bandwidth is used.

If I set a download cap -- any cap below the average download speed -- the upload bandwidth instantly begins dropping. Lower download caps == lower upload bandwidth.

If I set the download cap back to 0, the upload bandwidth instantly returns to 25KB/s.

If I set a download cap and then set the downloading priority of the files to "don't download", the upload bandwidth remains low until all currently downloading blocks finish, at which point the upload bandwidth jumps instantly back up to 25KB/s.

If I return the priority of the files to "normal", the upload bandwidth remains at 25KB/s until the download bandwidth reaches the download cap, at which point the upload bandwidth drops substantially.

I think what is happening is that the incoming acknowledgment traffic is being throttled along with the downloaded data, which shouldn't be happening. Incoming acknowledgments should always have priority over download data.

The effect is more pronounced as you raise the maximum number of allowed connections per torrent. At a setting of 1-4, upload bandwidth might only drop 25%. At a setting of 50, upload speeds can drop to almost nothing.

Removing the upload bandwidth cap doesn't help.

If this is happening to everyone, it could really harm the swarm!

Is there any way around this? Should this be submitted as a bug? Am I the only one who experiences this effect?

-cwm9

[Switeck]

It is a bug, it is know, and it would've been fixed...but µTorrent got bought out by BitTorrent so it may not get fixed now.

[Ultima]

http://forum.utorrent.com/viewtopic.php?id=18288

The (probably) next most-recent time that this behavior was reported was just 4 days ago too