Narf_the_Mouse: No sorcery, it's probably using torrents - I see the same speed increase with torrents. Torrents, BTW, are perfectly legal as long as the files being transfered are legal. It's also safe, since modern key encryption (such as the hash to make sure you're getting the right file pieces) is nearly impossible to break (by "nearly impossible", I mean "probably the death of the universe first for many of them, with current technology"). Most successful hacks are PEBKAC - Problem Exists Between Keyboard And Chair. The rest are "no known defense yet".

As for why it's faster, torrenting is called file-sharing for a reason, and it's both what and not what you think - Everyone on the network is both a potential downloader and a potential uploader. If you're getting a file from thirty different places, each uploading at, say, 80 KB/sec, that's 2,400 KB/sec, provided your connection can handle it.

If you're downloading from a "traditional" server, then their maybe 1 GB/sec could be shared among 5,000 people, resulting in 214 KB/sec.

How's that for an explanation? :)

cjrgreen: It's not using torrents, but it's doing almost the same thing using more conventional servers and protocols.

What the downloader does is spawn a whole swarm of connections, each one downloading a chunk of the file. The downloader's options dialog controls how many connections it will open: 1 to 10, default 6 last time I looked.

Often this gives you much better bandwidth utilization than the single connection that an HTTP or FTP download will use, because your PC is receiving on other connections while it is ACKing on one.