I am confused by what everyone says. Wouldn't 16ths in 4/4 timing at 250 bpm be 1000 plucks in a minute (or about 17 a second?) Is that possible even for 10 seconds? Are you saying that you can hit a note 170 times in 10 seconds? I know I am fairly slow but thats probably atleast 4 times faster than me.
I don't usually play that fast, but sometimes it's very fun to shred a little on bass to get some hand warm-ups in there, and it's actually in one of my songs that I use my speed-finger technique. It's like a three finger walk but I double pick with each finger, y'know? Imagine yourself picking with three of your fingers and as your ring finger gets in place to pick again, instead of avoiding the string, you just go across it. It essentially just turns it into a six finger walk or a small fanning motion. The timing is slightly different in order for it to actually be a separate note from the index finger, but that is what I do. I think it's somewhere from 18-24 notes a second. If you don't think it's possible, essentially what you do is look at your ring finger, and see if you can finger the string in (what I'll call up-strokes for a better image) 3 or 4 times in a second, if you can, then just multiply it by six if you have perfect technique.
I can hold that speed for a minute before I get bored with it, I think I might be able to do three or four minutes, but I haven't tried it so I won't even claim I can.
Having nails makes it sound sort-of sloppy, so if you can find a way to cover the nail or just cut them short enough to where you only use your finger tips then it'd sound much smoother.
I only use this in short bursts, like a solo/breakdown intro/outro (sliding up the neck going faster and to zenith for example) or other like situations where you want a surge of energy for more hard rock guys. Hell, maybe even metal, with their crazy chug patterns
A good way to practice technique is to jam with a drummer, and have him do snare rolls and you keep up with the snare strikes. Sounds ridiculous, but that's what I do with mine.
i'm sure their is a name for this, but I don't know what it is, I didn't even know what three finger walking was before I "discovered" this.