Why doesn BitTorrent obey the rate limits I selected?
Try enabling Limit local peer bandwidth. If you have limited your download rate, but BitTorrent isn’t obeying it, then take note the fact that BitTorrent cannot control how fast peers send data to it. As a result, download rate limiting is often inaccurate. In addition, setting download rate limits may cause your upload rates to suffer because of the way download rate limiting had to be implemented.