Comparing BitTorrent clients in the wild: the case of download speed

Abstract—BitTorrent (BT) is currently the main P2P protocol used for sharing large files over the Internet. It is therefore important to understand the performance characteristics of existing real-world BT implementations (clients). In this work, we measure the download speed of over 10 million BT users over one month. Surprisingly, our measurements show that the two most famous BT clients, namely uTorrent and Vuze (Azureus), achieve different download speeds for the same set of torrents. In particular, we observe that uTorrent users achieve 16 % faster download speed than users of Vuze in our data set. To shed light to the cause of this difference, we reverse engineer the two clients to infer their individual design choices. Our study shows that the two clients differ in two important areas: (a) how they manage their neighborhood, and (b) how they distribute their upload capacity to their peers. We speculate that the cause of the mismatch in download speeds can be attribute to these differences. We hope that our findings will open the door for new research efforts to better understand the impact of design choices in the performance of real-world BT implementations. I.