8 ms·

Article says at one point, "We have reduced the time for the computation by ~119%!", which is impossible. If you reduce it by 100% it is taking zero time alrea

by w0mbat 4y ago

Article says at one point, "We have reduced the time for the computation by ~119%!", which is impossible. If you reduce it by 100% it is taking zero time already.

nerdbaggy 4y ago
I always get confused by stuff with this. 100% would actually be 50% in the context you are thinking. https://math.stackexchange.com/a/1404242 https://math.stackexchange.com/a/1404242
Panzer04 4y ago
"faster" vs "reduced time". Many people confuse rate of work with reduction in time, and it's exceptionally annoying :(
- pindab0ter 4y ago
  Bonus points if the 'speed is faster'.
  - necovek 4y ago
    That one might not be strictly correct (speed is greater), but it's at least non-ambiguous and understandable. I love me some of those "discount -50%" signs though.
  - hinkley 4y ago
    Oh, but we let people say "acceleration is faster". It's like we've reserved 'faster' for a single derivative and banned it for all the others.
    - pindab0ter 4y ago
      I don't think it's about banning words at all. It's about words making sense. "What's cheaper? The price is." Now that just doesn't make any sense, since a price isn't cheap or expensive, it's high or low. The thing that is priced can be cheap or expensive, but that's not what's being said. "What's faster? The speed is." Doesn't make sense either. Speed isn't fast, the speedy thing is. However, "What's faster? The acceleration is." is fine, because you can have slow or fast acceleration (I think?). I'm an ESL speaker, so please do tell me if I'm wrong and how.
- necovek 4y ago
  But it's not only that. Nothing can be improved to be 119% faster either. Maybe the new result makes the old one 119% slower. It's about language use and what of are those per-cents (per-hundredths).
  - gilbetron 4y ago
    If I travel 25 miles in 1 hour, my speed was 25mph. If I go 100% faster, I'm going 50mph and get there in 30 minutes. If I go 200% faster, I'm going 75mph and get there in 20 minutes. However, the original statement of "We have reduced the time for the computation by ~119%!" is still wrong-seeming, I agree. It should be "We have increased the speed for the computation by 119%" or "We have reduced the time for the computation by <WHATEVER>" :)
    - necovek 4y ago
      Language is, as you nicely point out, very tricky. Yeah, when talking of speed, you can clearly go more than 100% faster. But when talking of something taking a certain amount of time, like done in most benchmarks, it can't be made more than 100% faster.
      - gilbetron 4y ago
        You can because when you say 100% faster, it is referring to speed, and so you convert to speed than calculate time from that. Language matters :)
        hinkley 4y ago
        > We have reduced the time for the computation by ~119%! You can say 100% faster when you are talking about speed. You can't say 100% faster when you are talking about duration. "Reduced the time" is talking about duration.
cozzyd 4y ago
That branch predictor is working really well!
- danybittel 4y ago
  Isn't it crazy how the branch predictor is something like 99% percent correct. Which means a computer is almost deterministic, it almost knows the future. A tiny bit better and we wouldn't need to show up in office. Of course multiply this by the sheer number of calculations and even that little misprediction results in huge differences. The reality is actually quite sobering: a computer mostly calculates the same thing over and over.
  - imtringued 4y ago
    When you execute a loop 1000 times it is only going to change branches once the loop finishes. If you always predict that the loop didn't finish, your branch predictor will correctly predict 99.9% of branches.
  - skohan 4y ago
    That’s a realization that made me a better programmer. I think when I was younger, I thought of programming as very open ended. I.e. I wanted to build abstract, general solutions which would be able to handle any future case. Over time I realized the problem space is mostly quite well defined, and when I started thinking about programming as defining an assembly line for computations my results and time to solution improved.
necovek 4y ago
People like to talk in percentages when it's obviously unclear what it means, and they frequently get it wrong. It gets even better when people start switching between percentages and "percentage points" referring to a measure that's in percentages originally. Unfortunately, most of those things are easier communicated and harder to get wrong if you try speaking in a more natural way. This is now "twice as fast" or "2.1x faster" is much clearer and can't go past zero :) Similarly, I think it'd help to switch back from percentages to actual factors (119% = 1.19), and saying "we reduced the time for the computation by 1.19 of original time" would clearly show what's wrong (and saying "by 1.19x" would signal how it's a small reduction, so it's wrong as well). Finally, I am 94.8% certain people will keep using percentages even where inappropriate, and with too much precision too!
- Agentlien 4y ago
  I work primarily with optimizations and depending on context I will express them in how much time it shaves off one iteration ("this saves 1 ms!"), the change in frame rate ("went from 20-22 fps to a stable 26 fps"), or the ratio between before and after ("it's twice as fast", "only takes one third of the time it used to!", ...)
- blindmute 4y ago
  I like to write "Takes X% of the time it took before" for maximum disambiguation

by w0mbat 4y ago

Article says at one point, "We have reduced the time for the computation by ~119%!", which is impossible. If you reduce it by 100% it is taking zero time already.

nerdbaggy 4y ago

I always get confused by stuff with this. 100% would actually be 50% in the context you are thinking. https://math.stackexchange.com/a/1404242 https://math.stackexchange.com/a/1404242

Panzer04 4y ago

"faster" vs "reduced time". Many people confuse rate of work with reduction in time, and it's exceptionally annoying :(

pindab0ter 4y ago
Bonus points if the 'speed is faster'.
- necovek 4y ago
  That one might not be strictly correct (speed is greater), but it's at least non-ambiguous and understandable. I love me some of those "discount -50%" signs though.
- hinkley 4y ago
  Oh, but we let people say "acceleration is faster". It's like we've reserved 'faster' for a single derivative and banned it for all the others.
  - pindab0ter 4y ago
    I don't think it's about banning words at all. It's about words making sense. "What's cheaper? The price is." Now that just doesn't make any sense, since a price isn't cheap or expensive, it's high or low. The thing that is priced can be cheap or expensive, but that's not what's being said. "What's faster? The speed is." Doesn't make sense either. Speed isn't fast, the speedy thing is. However, "What's faster? The acceleration is." is fine, because you can have slow or fast acceleration (I think?). I'm an ESL speaker, so please do tell me if I'm wrong and how.
necovek 4y ago
But it's not only that. Nothing can be improved to be 119% faster either. Maybe the new result makes the old one 119% slower. It's about language use and what of are those per-cents (per-hundredths).
- gilbetron 4y ago
  If I travel 25 miles in 1 hour, my speed was 25mph. If I go 100% faster, I'm going 50mph and get there in 30 minutes. If I go 200% faster, I'm going 75mph and get there in 20 minutes. However, the original statement of "We have reduced the time for the computation by ~119%!" is still wrong-seeming, I agree. It should be "We have increased the speed for the computation by 119%" or "We have reduced the time for the computation by <WHATEVER>" :)
  - necovek 4y ago
    Language is, as you nicely point out, very tricky. Yeah, when talking of speed, you can clearly go more than 100% faster. But when talking of something taking a certain amount of time, like done in most benchmarks, it can't be made more than 100% faster.
    - gilbetron 4y ago
      You can because when you say 100% faster, it is referring to speed, and so you convert to speed than calculate time from that. Language matters :)
      - hinkley 4y ago
        > We have reduced the time for the computation by ~119%! You can say 100% faster when you are talking about speed. You can't say 100% faster when you are talking about duration. "Reduced the time" is talking about duration.

cozzyd 4y ago

That branch predictor is working really well!

danybittel 4y ago
Isn't it crazy how the branch predictor is something like 99% percent correct. Which means a computer is almost deterministic, it almost knows the future. A tiny bit better and we wouldn't need to show up in office. Of course multiply this by the sheer number of calculations and even that little misprediction results in huge differences. The reality is actually quite sobering: a computer mostly calculates the same thing over and over.
- imtringued 4y ago
  When you execute a loop 1000 times it is only going to change branches once the loop finishes. If you always predict that the loop didn't finish, your branch predictor will correctly predict 99.9% of branches.
- skohan 4y ago
  That’s a realization that made me a better programmer. I think when I was younger, I thought of programming as very open ended. I.e. I wanted to build abstract, general solutions which would be able to handle any future case. Over time I realized the problem space is mostly quite well defined, and when I started thinking about programming as defining an assembly line for computations my results and time to solution improved.

necovek 4y ago

People like to talk in percentages when it's obviously unclear what it means, and they frequently get it wrong. It gets even better when people start switching between percentages and "percentage points" referring to a measure that's in percentages originally. Unfortunately, most of those things are easier communicated and harder to get wrong if you try speaking in a more natural way. This is now "twice as fast" or "2.1x faster" is much clearer and can't go past zero :) Similarly, I think it'd help to switch back from percentages to actual factors (119% = 1.19), and saying "we reduced the time for the computation by 1.19 of original time" would clearly show what's wrong (and saying "by 1.19x" would signal how it's a small reduction, so it's wrong as well). Finally, I am 94.8% certain people will keep using percentages even where inappropriate, and with too much precision too!

Agentlien 4y ago
I work primarily with optimizations and depending on context I will express them in how much time it shaves off one iteration ("this saves 1 ms!"), the change in frame rate ("went from 20-22 fps to a stable 26 fps"), or the ratio between before and after ("it's twice as fast", "only takes one third of the time it used to!", ...)
blindmute 4y ago
I like to write "Takes X% of the time it took before" for maximum disambiguation