The core cause for this is overloading your router. The patcher has a peer-to-peer option that allows you to share some of the patch data with several other players, which speeds up their patch speed – other players are doing this for your which speeds up your patch speed – sort of a community helping each other out for the greater good. This works exactly how Bit Torrent functions. Strength in numbers.
The long standing problem with this is that the patcher comes, in my professional opinion, misconfigured by default. It's set to open up 600 connections, or try to. While the average computer that can run Star Citizen can easily handle 600 connections, the average household router cannot. The average household router ends up spending more time trying to manage the 600 connections than it does actually handling data coming from and to the Internet, which is why it seems that the Internet connection begins to choke when patching Star Citizen data.
The fix is actually pretty simple and doesn't require any special skills or software:
- Close the Star Citizen Patcher.
- Browse to C:\Program Files\cloud imperium games\Patcher (If you installed elsewhere, you should know where that is.)
- Open the file _TorrentSettings with your favorite text file editor (Notepad works for most people).
- Change connections_limit from 600 to 100 or less. (I went with 50 and was still able to max my download speed.)
- Save the file and close your text editor.
- Test it out! If you still have problems, reduce the value for connections_limit further until you no longer experience the issue.