Here is a guitar technique that if mastered, would allow you to hit a flurry of notes in one whip. You can’t possibly do this with alternate picking. This would allow you to play two or more notes in a string adjacent to each other, using one sweeping motion, whether downwards or upwards. So if you want to learn more about this subject matter, there is only one method that I could suggest: read this post. Yes, simply read this. That is if you want to avoid the trouble of Google – ing it and ending up on a paid website that won’t allow you to see anything unless you pay for it. Save yourself from that trouble and read his post. And by the time you finish reading it, you would become informed about it and you will have the tools necessary to practice it.
For example, you have to do an arpeggio on three notes on three adjacent strings. Now, this is the perfect situation in which you could use sweep picking. Instead of picking it one by one or doing alternate picking on their behinds, you could sweep your way down to that three notes. The result, faster note picking.