I like using notes-per-second as an objective figure that doesn’t have to be quantified by anything else. For rhythmic values we have to state the subdivision and the tempo, for notes per second we can just give one number.
Depending on context we might be working with 16ths, 8th triplets, 16th triplets, 32nd, etc etc or even quintuplets, so the NPS thing just simplifies the data we really care about for the discussion
Its probably my inability to convert nps into anything meaningful that puts me off! If someone says to me 13nps, I have to get the calculator out to know what the hell they are talking about! 
Whereas I can look at a tab book at the bpm and the highest subdivision in the song and know the likelyhood of me being able to play it with my current technique…
An easy way to convert from nps to BPM is to think in sextuplets:
X notes per second is equivalent to 6 notes per beat at X*10 BPM
10 nps → 6s at 100bpm
11 nps → 6s 110bpm
…
13 nps → 6s at 130 bpm
and so on 
This conversion method makes sense.
I too, have always had a hard time doing conversion math.
I can’t do it in my head quickly, I made a chart - feel free to copy and edit for your own use:
(related thread
but yeah the numbers don’t ‘mean’ anything to me, but then when I punch them into note values they have more context.
Also people talk about triplets for this stuff but for whatever reason I just rarely have been working with long streams of triplets, so I always have to convert to 16ths anyway
When I worked in the print industry, we were trained on the psychology of grayscale perception, text “color,” and what not. I’ve often wondered what measurable crossovers in perception exist. Not between being able to play something or not, but rather, whether one perceives something as shred. Some of you have touched upon it, and “I know it when I [hear] it,” but I’d like to see it explored more.
Maximum speed is far less interesting to me, having long since broken through the 16ths at 110 or so ceiling in my past.
Interesting topic. Thanks. D
I’d actually like to hear your thought on this crossover perception.
I think you’ve touched on a really good point here.
I recently was listening to Warren DiMartini (Ratt) recently and thought this exact thing you’ve brought up.
There was a section in a solo that wasn’t played fast per se, but I. The context of that song, in that solo it sounded fast.
From a purely mechanical standpoint, I’ve wanted to see what top speeds are for various patterns, like string alternating, skipping, etc. The reason I think its valuable is that many guitarists tend to avoid certain patterns, because they think picking them is just not feasible… and that avoidance can lead to problems down the road.
But from a ‘perception’ standpoint… I think clean alternate picking at around 175ish 16th notes… can sound jaw-dropping. It’s all in the technique.
At least for cross-picking it’s not too hard to guess: it’s around 9 to 11 notes per second. If what Troy said on the Steve Morse excerpt about Tumeni Notes’ tempo, that’s where the song sits. 209BPM multiplied by three notes per beat, all that divided by 60 seconds equals 10.45 notes per second. If Dream Theater’s Glass Prison arpeggios are truly around 170BPM, they’re just over 11 notes per second.
On a single string (tremolo picking), the maximum recorded by the CtC team is 24 NPS, and several instances of 21NPS as well.
I think there are probably people on this forum who can go beyond 11 notes per second for certain one-note-per-string alt-picking patterns for short periods of time. A lot of us are just starting X-picking … so our speed limits are changing quickly. I am really curious about string skipping alternating, 3 string rolls, string skipping asc/desc, etc.
The way I see it there’s two different angle for ‘speed’. First is the maximum speed you can get for a given lick that you learn, gradually cranking the metronome. Second is what I call the ‘comfort’ speed, which is the speed you are comfortable with on a given technique (or picking strategy), not necessariy applied to a pet lick. I’m much more interested in the second which obviously is slower, but has way more practical applications, especially for improvisation.
For that reason I almost never use a metronome to work on speed, because the ‘comfort speed’, by definition, is not monitored from an external metronome (it’s more tied to an internal metronome so to speak). Obviously your maximum speed naturally increases when your comfort speed increases, and that is what matters to me.
I think most shredders play to fast. In my opinion if you can get to the level of speed that Eric Jonhson plays at like on his Austin City Limits performance you’re good to go. That’s at around 170-200 BPM I believe. It’s fast but doesn’t start to become a blur to where you can’t distinguish the notes or even what scale they’re even playing. Seriously how useful is it 98% of the time to play as fast as Rusty Cooley?? It’s starts to become non musical I.M.O
I agree that sometimes too fast is well, too fast.
But are you saying that you don’t consider EJ a shredder?
I realize that he is stylistically pretty different from what is typically considered a shred style but I still see him as a shredder-type.
I consider him a shredder but he’s very smart knowing when to do it and like I said before he knows he’s playing about as fast as you really should. If you get up to the levels of speed like Paul Gilbert that’s great too, but not a necessity I think.
Oh yeah, his sense of melody is ridiculous
Aye. With regard to perception, EJ seems a great example of someone who doesn’t necessarily play as fast as the next person, but his lines evoke “shred.” The example I find myself referring to is Neil Schon, whose fast lines rip out of nowhere.
Sort of like, when all one’s mountain climbs are 14’ers from 13,000ft, I suspect it’s not quite as exciting as sea level to 10,000ft…
So, yeah, “shred” likely comprises some combination of perceptual contrast. And I think tone and articulation factors into that as well. Nail those elements and we have something beside raw nps to strive for, each in our own way.
Thanks! I’ve been programming in other industries for quite awhile now and don’t necessarily remember what I told folks dealing with banding in gradient blends on the phone with service bureaus circa 1993, but I can speak to the point generally.
The human eye can only distinguish roughly thirty or so different shades (again, don’t recall the exact studies) of gray when presented with them to compare. Create a fancy blend in a desktop publishing program on screen, and get your dots per inch (dpi) wrong relative to your printed “line screen” (ls), and you will end up with something that looks striped instead of blended when printed. In terms of failure, this approaches “ls equal to dpi” which might look fantastically blended in millions of colors on a computer screen, but which on the printing press would result in only two rectangles, one white, one black! Hence “half-toning” where the dots taken together imply detail in less resolution. (Oh goodness, that’s a lot of jargon! And don’t get me started on the loudness war in audio…)
Basically, the highest resolution produceable doesn’t necessarily equate to what one wants.
I get what you’re driving at. That’s actually an interesting correlation to guitar playing! Two seemingly different things share a lot of commonality.
All this talk of speed and what have I been working on lately…learning Jeff’s beck’s lines in “People get Ready”. Lol
Talk about a master of phrasing.
I wasn’t aware EJ ever played over 170.
I think 200+ BPM is musical in moderation. Like doing a sudden ascending scale can be really powerful (Ex: the buildup to the E.T. flying theme)
When I’m practicing, if I hit 200 BPM for a phrase… I don’t ever think… hmmm… I wonder if I can go faster. I just try and clean it up, and maintain it. Most of my practicing is with phrases that are much slower… stuff in the 130-170 zone. That’s the ‘under construction’ speed.
As far as Hyper-picking… I can’t hear anything past about 240 bpm. It really just becomes a rumbling sound. And honestly… almost nobody can reliably sync their picking/fretting past 260 bpm. And even if they can… who could honestly tell? I think John Taylor has said basically the same thing.