6 ms·

In a lot of circles, especially where web developers are involved, you'll get called out for premature optimization for spending any mental energy worrying abou

by adrusi 11y ago

In a lot of circles, especially where web developers are involved, you'll get called out for premature optimization for spending any mental energy worrying about memory usage or bandwidth. The idea is that computers are fast, so we can just do whatever we want, and worry about it if it becomes a problem. The result is that it becomes a problem, then gets patched up to meet whatever bare minimum performance standards the company has (or the deadline arrives and it's released unoptimized) and we end up with the absurdly heavy and resource-greedy software we see today.

hire_charts 11y ago
Yes, this is where, in practice, I've seen the adage used incorrectly. Even when Knuth isn't quoted directly, the idea that "premature optimization" is inherently a bad thing has led many a web developer down the path of terrible architecture decisions. So I understand Duffy's point exactly. It's not that all issues are preventable. It's that you can prevent a lot of them with just a little extra work up front. It's a misuse of Knuth's original point, which has much more to do with how brittle and incomprehensible "optimized" code can become.
- ubernostrum 11y ago
  I prefer the development order of make it work, make it correct, then make it fast. Expresses a similar idea, but in terms of priorities instead of "don't do that at all".
  - vmorgulis 11y ago
    > Expresses a similar idea, but in terms of priorities instead of "don't do that at all". The programming language affects a lot the criterion. Some are known to be "correct" (like Haskell), others "fast" (like C) ... Given an infinite amount of time, I suppose the three can be reached in any language.
Swizec 11y ago
It's a cost optimization. How much engineer time does it take to shave 0.2 seconds off of an action that's got a 0.3s animated transition anyway? How much engineering does it take to care about the memory footprint of a website users are going to close in 5 minutes anyway? Most of the time, the answer is "Too much, not worth it". Some of the time the answer is "Let's do it". Knowing which situation you are in is key. Ideally, I should write code for readability and maintainability and let the compiler and runtime worry about optimizations.
- kuschku 11y ago
  And that’s when people start using script blockers and block many CSS features just to be able to load + display webpages in ping + 16ms.
- yongjik 11y ago
  No opinion about the rest of the argument, but a 300ms animated transition is looooooong. It will be noticed by basically everybody and annoy a good number of them. The only good reason I can think of is that you're somehow stuck with 300ms+ delay anyway, so you provide an animation so that the users don't think "WTF? I just clicked on it and why is nothing happening?" But if you can shave off 0.2 seconds then you can probably get rid of the animation altogether!
  - Swizec 11y ago
    You'd be surprised by how many people think those 300ms animated transitions are a good thing. I think they're terrible. You'd also be surprised by how many people will completely misunderstand your UI and get confused by things popping around magically, if the transitions are too fast or inexistent. You have to build a UI/UX that your typical user will enjoy and be able to use, not a UI/UX that your nerdy friends are going to love. (unless they're your target users)
    - mrob 11y ago
      The only good UI animations I've seen were in Metacity (window manager for Gnome 2). It would move windows instantly, but also provide a transparent trail showing the path they would have taken if they had been animated traditionally. It let you continue working without delay if you knew what you were doing while still helping beginners.
nostrademons 11y ago
From a business perspective, this is probably the right decision. Businesses are interested in marginal gains, i.e. they want performance improvements only if those will lead to more customers or customers that pay more money. Any extra effort is better spent on things that will get more customers or more money per customer. From an overall social welfare pesrpective, there is something to be said for going above and beyond the customer's minimum standard. Indeed, most of the work that goes on at big companies is of this type (it's no coincidence that the original author works on the compiler team at Microsoft). Just understand the context in which you work - if the company is going to go under with its current customer base, it's irresponsible to focus on things that are not going to get more customers - and that it can be hard to measure the effectiveness of work that doesn't directly lead to new sales.
- acqq 11y ago
  > From an overall social welfare pesrpective, there is something to be said for going above and beyond the customer's minimum standard. Indeed, most of the work that goes on at big companies is of this type So do you want to say that MSFT should invest less energy in speeding up the code they produce, because it won't get them more customers or more money?
  - nostrademons 11y ago
    From which perspective do you want an answer? A user of Microsoft products, a developer at Microsoft, a shareholder of Microsoft, or an executive of Microsoft? As a user, of course I want Microsoft to invest more in speeding up their products. I also want them to be easier to use, and have all the features that I want, and cost less, and release more frequently. As an engineer, yes, I do want them to invest more in speeding up products. Performance tuning is fun, it's an extra skill that can go on my resume, and it helps me take pride in my work. As a shareholder, hell no are you going to indulge those prima donna engineers and their perfectionist tendencies. I invested in this company to get a return on my investment, and that means more revenue. It's clear that shaving CPU cycles isn't going to get more customers; Windows has been dog-slow compared to competitors ever since the Amiga came out, and it hasn't hurt us so far. That effort would be better invested in getting into new lines of business and building more solutions to capture the enterprise market. As an executive - it's a complicated question. I want our products to be faster, but it's also clear that our customers want them to be easier to use, and have a lot more features, and cost less, and release more frequently. All of those are in conflict with writing performant code with a fixed number of highly-trained engineers. And if I hire more engineers, the code often gets slower, as global optimization opportunities get lost in the communication gaps between workers. OTOH, performance often has intangible benefits in brand loyalty, in increased usage, in word-of-mouth, and in PR. I'd love to be able to quantify these benefits and trade them off against each other, but the point of intangibles is that they are intangible. I'm responsible to shareholders, however, and my gut feeling is that increased performance will not be the deciding factor for most customers. (As just plain old me, the question is completely academic: I am neither a user, employee, executive, or shareholder of Microsoft, so I don't really care what they do.)
blakeyrat 11y ago
Well the salient word in the phrase is "premature". As opposed to optimization after careful observation and measurement, which everybody agrees can and should be done.
- svdree 11y ago
  But at the point where you're ready for careful observation and measurement, you've already designed and written your solution, and the amount of room you have for optimization is constrained by the thing you just built. If you want performance, you have to design for performance, not just build the first thing that comes to mind and try to optimize it later.
deleted 11y ago
[deleted]
dhimes 11y ago
Interesting. I always interpreted it as, "Don't sweat the details yet- you don't even know if anybody wants what you are building. Find that out first."
- mark-r 11y ago
  The mindset of "fail fast" wasn't a thing when Knuth wrote that statement.
  - dhimes 11y ago
    This isn't "fail" so much as it is acknowledging that neither you nor your customers will know what they like until they have something to play with.
    - mark-r 11y ago
      My point was that Knuth wasn't considering that possibility when he wrote the quote. In those times it was assumed that if you were writing software, there was a darn good reason for it. The idea that you might write software that doesn't fulfill a compelling need is a rather modern invention.
      - over 11y ago
        Except that optimizing cold code is writing software that doesn't fulfill a compelling need.
crdoconnor 11y ago
>In a lot of circles, especially where web developers are involved, you'll get called out for premature optimization for spending any mental energy worrying about memory usage or bandwidth. The idea is that computers are fast, so we can just do whatever we want, and worry about it if it becomes a problem. The result is that it becomes a problem, then gets patched up to meet whatever bare minimum performance standards the company has (or the deadline arrives and it's released unoptimized) and we end up with the absurdly heavy and resource-greedy software we see today. IMHO, this is exactly the kind of thing Donald Knuth was approving of. Given how cheap CPU cycles are, how expensive developers are and that faster code often means more 'unsafe' code, 97% of the time it's more economic to just have the resource-greedy software. Plus, I've seen more than my fair share of premature optimizations that ended up actually causing performance problems and stupid bugs.
- vmorgulis 11y ago
  > Given how cheap CPU cycles are, how expensive developers are and that faster code often means more 'unsafe' code, 97% of the time it's more economic to just have the resource-greedy software. I agree. I run sloccount in my build system. It gives a cost for manpower. For example: Total Physical (SLOC) = 6,944 Development (Person-Months) = 18.36 Schedule Estimate (Months) = 7.55 Estimated Average Number of Developers = 2.43 Estimated Cost to Develop = $ 206,696 http://www.dwheeler.com/sloccount/ http://www.dwheeler.com/sloccount/ http://vmorgulys.github.io/stackcity/sloccount.html http://vmorgulys.github.io/stackcity/sloccount.html We should count the energy spent by inefficient programs (multiply the number of devices). It could balance that equation as the Moore's Law is ending. I guess Debian (or another distro) if more energy-efficient than Windows (or Android). Edit: beautified sloccount output
maxxxxx 11y ago
I get into discussions like this all the time. With a little thinking ahead you can avoid getting yourself caught in a difficult situation later on. It doesn't mean you should implement the optimization but at least you should allow for it. That could mean a simple API wrapper that can later on be optimized or to do an analysis what would happen if the traffic increased 10x. Unfortunately looking further than the end of the next sprint is disallowed in a lot of people's minds. It's pretty sad that a lot of software "engineers" actively avoid any kind of engineering.
- gnaritas 11y ago
  It's not sad, that kind of "thinking ahead" leads too oodles of junk in the code for "someday" features that never get implemented. If your programming style requires thinking ahead to make a feature possible later, then you're better off fixing your style and learning to program better so it costs the same to make the change when it's needed as it does now, then you can put off the change until it's actually needed. Premature architecture is a code smell. Putting in scaffolding for later is a code smell.
  - maxxxxx 11y ago
    I am not talking about actually producing code for "someday" features. I am talking about working towards a goal. Most projects know pretty well where they will be in one or two years (not everyone is Instagram who goes from 0-100 in a year). Based on that knowledge you can make reasonable decisions and trade-offs now. However, I admire your ability to write code without any forethought now that can be used perfectly in whatever form it will be needed later.
    - gnaritas 11y ago
      > Most projects know pretty well where they will be in one or two years I dispute that that is true. They may have a vague idea of a goal, but that's not applicable at the code level in general. > Based on that knowledge you can make reasonable decisions and trade-offs now. We aren't talking about making decisions, we're talking about stubbing out code for future needs, an entirely different thing. Nothing wrong with making reasonable decisions, but there is something wrong with stubbing out code you don't need because you think you'll need it later; if you need it later, add it later. It'll cost the same as adding it now. If you think it's going to cost more later, then revisit your architecture because it shouldn't. The implicit argument for adding it now is that's it's cheaper to add now than later, I'm saying that's nearly always a bunk argument. > However, I admire your ability to write code without any forethought now that can be used perfectly in whatever form it will be needed later. That's not what I said; the cost of change should be the same later as now. That doesn't mean you won't have to make a change, it just means it shouldn't be harder to add later than to add now.
nyan4 11y ago
> web developers That's the problem.

by adrusi 11y ago

hire_charts 11y ago

Yes, this is where, in practice, I've seen the adage used incorrectly. Even when Knuth isn't quoted directly, the idea that "premature optimization" is inherently a bad thing has led many a web developer down the path of terrible architecture decisions. So I understand Duffy's point exactly. It's not that all issues are preventable. It's that you can prevent a lot of them with just a little extra work up front. It's a misuse of Knuth's original point, which has much more to do with how brittle and incomprehensible "optimized" code can become.

ubernostrum 11y ago
I prefer the development order of make it work, make it correct, then make it fast. Expresses a similar idea, but in terms of priorities instead of "don't do that at all".
- vmorgulis 11y ago
  > Expresses a similar idea, but in terms of priorities instead of "don't do that at all". The programming language affects a lot the criterion. Some are known to be "correct" (like Haskell), others "fast" (like C) ... Given an infinite amount of time, I suppose the three can be reached in any language.

Swizec 11y ago

It's a cost optimization. How much engineer time does it take to shave 0.2 seconds off of an action that's got a 0.3s animated transition anyway? How much engineering does it take to care about the memory footprint of a website users are going to close in 5 minutes anyway? Most of the time, the answer is "Too much, not worth it". Some of the time the answer is "Let's do it". Knowing which situation you are in is key. Ideally, I should write code for readability and maintainability and let the compiler and runtime worry about optimizations.

kuschku 11y ago
And that’s when people start using script blockers and block many CSS features just to be able to load + display webpages in ping + 16ms.
yongjik 11y ago
No opinion about the rest of the argument, but a 300ms animated transition is looooooong. It will be noticed by basically everybody and annoy a good number of them. The only good reason I can think of is that you're somehow stuck with 300ms+ delay anyway, so you provide an animation so that the users don't think "WTF? I just clicked on it and why is nothing happening?" But if you can shave off 0.2 seconds then you can probably get rid of the animation altogether!
- Swizec 11y ago
  You'd be surprised by how many people think those 300ms animated transitions are a good thing. I think they're terrible. You'd also be surprised by how many people will completely misunderstand your UI and get confused by things popping around magically, if the transitions are too fast or inexistent. You have to build a UI/UX that your typical user will enjoy and be able to use, not a UI/UX that your nerdy friends are going to love. (unless they're your target users)
  - mrob 11y ago
    The only good UI animations I've seen were in Metacity (window manager for Gnome 2). It would move windows instantly, but also provide a transparent trail showing the path they would have taken if they had been animated traditionally. It let you continue working without delay if you knew what you were doing while still helping beginners.

nostrademons 11y ago

From a business perspective, this is probably the right decision. Businesses are interested in marginal gains, i.e. they want performance improvements only if those will lead to more customers or customers that pay more money. Any extra effort is better spent on things that will get more customers or more money per customer. From an overall social welfare pesrpective, there is something to be said for going above and beyond the customer's minimum standard. Indeed, most of the work that goes on at big companies is of this type (it's no coincidence that the original author works on the compiler team at Microsoft). Just understand the context in which you work - if the company is going to go under with its current customer base, it's irresponsible to focus on things that are not going to get more customers - and that it can be hard to measure the effectiveness of work that doesn't directly lead to new sales.

acqq 11y ago
> From an overall social welfare pesrpective, there is something to be said for going above and beyond the customer's minimum standard. Indeed, most of the work that goes on at big companies is of this type So do you want to say that MSFT should invest less energy in speeding up the code they produce, because it won't get them more customers or more money?
- nostrademons 11y ago
  From which perspective do you want an answer? A user of Microsoft products, a developer at Microsoft, a shareholder of Microsoft, or an executive of Microsoft? As a user, of course I want Microsoft to invest more in speeding up their products. I also want them to be easier to use, and have all the features that I want, and cost less, and release more frequently. As an engineer, yes, I do want them to invest more in speeding up products. Performance tuning is fun, it's an extra skill that can go on my resume, and it helps me take pride in my work. As a shareholder, hell no are you going to indulge those prima donna engineers and their perfectionist tendencies. I invested in this company to get a return on my investment, and that means more revenue. It's clear that shaving CPU cycles isn't going to get more customers; Windows has been dog-slow compared to competitors ever since the Amiga came out, and it hasn't hurt us so far. That effort would be better invested in getting into new lines of business and building more solutions to capture the enterprise market. As an executive - it's a complicated question. I want our products to be faster, but it's also clear that our customers want them to be easier to use, and have a lot more features, and cost less, and release more frequently. All of those are in conflict with writing performant code with a fixed number of highly-trained engineers. And if I hire more engineers, the code often gets slower, as global optimization opportunities get lost in the communication gaps between workers. OTOH, performance often has intangible benefits in brand loyalty, in increased usage, in word-of-mouth, and in PR. I'd love to be able to quantify these benefits and trade them off against each other, but the point of intangibles is that they are intangible. I'm responsible to shareholders, however, and my gut feeling is that increased performance will not be the deciding factor for most customers. (As just plain old me, the question is completely academic: I am neither a user, employee, executive, or shareholder of Microsoft, so I don't really care what they do.)

blakeyrat 11y ago

Well the salient word in the phrase is "premature". As opposed to optimization after careful observation and measurement, which everybody agrees can and should be done.

svdree 11y ago
But at the point where you're ready for careful observation and measurement, you've already designed and written your solution, and the amount of room you have for optimization is constrained by the thing you just built. If you want performance, you have to design for performance, not just build the first thing that comes to mind and try to optimize it later.

deleted 11y ago

[deleted]

dhimes 11y ago

Interesting. I always interpreted it as, "Don't sweat the details yet- you don't even know if anybody wants what you are building. Find that out first."

mark-r 11y ago
The mindset of "fail fast" wasn't a thing when Knuth wrote that statement.
- dhimes 11y ago
  This isn't "fail" so much as it is acknowledging that neither you nor your customers will know what they like until they have something to play with.
  - mark-r 11y ago
    My point was that Knuth wasn't considering that possibility when he wrote the quote. In those times it was assumed that if you were writing software, there was a darn good reason for it. The idea that you might write software that doesn't fulfill a compelling need is a rather modern invention.
    - over 11y ago
      Except that optimizing cold code is writing software that doesn't fulfill a compelling need.

crdoconnor 11y ago

>In a lot of circles, especially where web developers are involved, you'll get called out for premature optimization for spending any mental energy worrying about memory usage or bandwidth. The idea is that computers are fast, so we can just do whatever we want, and worry about it if it becomes a problem. The result is that it becomes a problem, then gets patched up to meet whatever bare minimum performance standards the company has (or the deadline arrives and it's released unoptimized) and we end up with the absurdly heavy and resource-greedy software we see today. IMHO, this is exactly the kind of thing Donald Knuth was approving of. Given how cheap CPU cycles are, how expensive developers are and that faster code often means more 'unsafe' code, 97% of the time it's more economic to just have the resource-greedy software. Plus, I've seen more than my fair share of premature optimizations that ended up actually causing performance problems and stupid bugs.

vmorgulis 11y ago
> Given how cheap CPU cycles are, how expensive developers are and that faster code often means more 'unsafe' code, 97% of the time it's more economic to just have the resource-greedy software. I agree. I run sloccount in my build system. It gives a cost for manpower. For example: Total Physical (SLOC) = 6,944 Development (Person-Months) = 18.36 Schedule Estimate (Months) = 7.55 Estimated Average Number of Developers = 2.43 Estimated Cost to Develop = $ 206,696 http://www.dwheeler.com/sloccount/ http://www.dwheeler.com/sloccount/ http://vmorgulys.github.io/stackcity/sloccount.html http://vmorgulys.github.io/stackcity/sloccount.html We should count the energy spent by inefficient programs (multiply the number of devices). It could balance that equation as the Moore's Law is ending. I guess Debian (or another distro) if more energy-efficient than Windows (or Android). Edit: beautified sloccount output

maxxxxx 11y ago

I get into discussions like this all the time. With a little thinking ahead you can avoid getting yourself caught in a difficult situation later on. It doesn't mean you should implement the optimization but at least you should allow for it. That could mean a simple API wrapper that can later on be optimized or to do an analysis what would happen if the traffic increased 10x. Unfortunately looking further than the end of the next sprint is disallowed in a lot of people's minds. It's pretty sad that a lot of software "engineers" actively avoid any kind of engineering.

gnaritas 11y ago
It's not sad, that kind of "thinking ahead" leads too oodles of junk in the code for "someday" features that never get implemented. If your programming style requires thinking ahead to make a feature possible later, then you're better off fixing your style and learning to program better so it costs the same to make the change when it's needed as it does now, then you can put off the change until it's actually needed. Premature architecture is a code smell. Putting in scaffolding for later is a code smell.
- maxxxxx 11y ago
  I am not talking about actually producing code for "someday" features. I am talking about working towards a goal. Most projects know pretty well where they will be in one or two years (not everyone is Instagram who goes from 0-100 in a year). Based on that knowledge you can make reasonable decisions and trade-offs now. However, I admire your ability to write code without any forethought now that can be used perfectly in whatever form it will be needed later.
  - gnaritas 11y ago
    > Most projects know pretty well where they will be in one or two years I dispute that that is true. They may have a vague idea of a goal, but that's not applicable at the code level in general. > Based on that knowledge you can make reasonable decisions and trade-offs now. We aren't talking about making decisions, we're talking about stubbing out code for future needs, an entirely different thing. Nothing wrong with making reasonable decisions, but there is something wrong with stubbing out code you don't need because you think you'll need it later; if you need it later, add it later. It'll cost the same as adding it now. If you think it's going to cost more later, then revisit your architecture because it shouldn't. The implicit argument for adding it now is that's it's cheaper to add now than later, I'm saying that's nearly always a bunk argument. > However, I admire your ability to write code without any forethought now that can be used perfectly in whatever form it will be needed later. That's not what I said; the cost of change should be the same later as now. That doesn't mean you won't have to make a change, it just means it shouldn't be harder to add later than to add now.

nyan4 11y ago

> web developers That's the problem.