141.101.98.47 08:33, 8 June 2016 (UTC) Yay! It is far less costly to design correctly considering the optimal code for the situation you expect than to wait until the there are a million users and people are screaming becasue you used cursors throughout the application. XKCD tells it all. As Knuth said, We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil. ... and then some more about the importance of profiling tools: It is often a mistake to make a priori judgments about what parts of a Premature optimization is spending a lot of time on something that you may not actually need. I've become convinced that all compilers written from now on should be To quote the immortal words of xkcd: “Premature optimization is the root of all evil.” EDIT: It has been pointed out to me the the original author of the “premature optimization” quote is in fact Donald Knuth, not xkcd. Premature optimization to me means trying to improve the efficiency of your code before you have a working system, and before you have actually profiled it and know where the bottleneck is. make the code harder to understand or maintain, hence "premature optimization is the root of all evil". 12% improvement, easily obtained, is never considered marginal; and I Anything longer than that isn't usually optimisation, it's bug fixing. measured improvement in server performance. It's worth noting that Knuth's original quote came from a paper he wrote promoting the use of goto in carefully selected and measured areas as a way to eliminate hotspots. edit: Incidentally, regarding the linked article, I would question many of the assumptions made. There is most definitely a time and place for optimisation. How to Be "Done Done" Make a little progress on every aspect of your work every day. premature optimization is the root of all evil. The title text's root of all evil refers to Donald Knuth's paper "Structured Programming with Goto statements" (1974)[1] in which he wrote: "There is no doubt that the grail of efficiency leads to abuse. A primary goal of software development teams is delivering valuable features and products as quickly and effectively as possible.One way they can optimize how quickly they deliver software is by leveraging methodologies … Optimizing for space instead of speed in C++. Another layer of humor is provided by the minimalism and directness of the flowchart, which suggests that it has itself been (prematurely?) Premature optimization can often end up backfiring, and cause you to waste a lot of resources, such as time, money, and effort, while also increasing the likelihood that you will create future problems. I apologize for this unfortunate omission, and hope that the readers will forgive me : ) [...] again, this is a noticeable saving in the overall running speed, We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil. No, using the more efficient one would not, in that case, be premature. However, the trick is to spend the extra cost only where it counts to the performance of the application and where the additional cost outweighs the performance hit. Remember: “Premature optimization is the root of all evil” (Donald Knuth). Of ... premature optimization is the root of all evil (or at least most of it) in … First time starting a page's explanation! Posted on 12 September 2016 by ecoquant. Avoiding premature optimization is about picking your battles. More details. Here's a related article by Randall Hyde called The Fallacy of Premature Optimization. Put the most common value first in a switch/case, etc. B) Even after performing all possible optimizations, you won't meet your goal performance threshold, and the low-level optimizations don't make enough difference in performance to justify the loss of readability. Since it would be handy to keep that branch in mind, its removal is clearly premature. In the past I've worked on some time critical code (an RSA implementation) where looking at the assembler that the compiler produced and removing a single unnecessary instruction in an inner loop gave a 30% speedup. Even after that, readability and maintainability should come before optimization in many cases. statements in this context]. (Score: 5, Informative) by LichtSpektren on Wednesday June 08, 2016 @11:48AM Sandboxing all of FF's plugins is good security practice. My question is, if a particular His quote was effectively a part of a big disclaimer, just like someone doing a motorcycle jump over a flaming fire pit might add a disclaimer that amateurs shouldn't try this at home while simultaneously criticizing those who try without proper knowledge and equipment and get hurt. Another question to ask yourself when optimising is "am I doing the equivalent of optimising for a 300 baud modem here?". Crucially, before embarking on a grand optimization adventure, make sure that the functions you are optimizing are actually the functions that you will want to use in the long run. This is something which often comes up in Stack Overflow answers to questions like "which is the most efficient loop mechanism", "SQL optimisation techniques?" Their code actually needs tuning, or; Their techniques actually work. Making toys/playable demos is great when learning new concepts but you need to actually finish games to understand what's required to make something start to finish. javascript required to view this site. If I understand correctly, Mozilla is re-writing their layout engine in Rust, which should be considerably more secure than Blink (Chrome's engine). Rule 5 was previously stated by Fred Brooks in The Mythical Man-Month. So, the first line is only true because the very fact that you are asking a question about whether or not optimization is premature means that you are not sure that you need optimization, which by definition makes it premature. A) You can reach the goal performance threshold by performing high-level optimizations, so it's not necessary to fiddle with the expressions. When programming, a number of parameters are vital. (Move immutable expressions outside of the loop body. But optimized code takes longer to write, and longer to maintain, and in this subideal world, we have limited time to spend on code. Among these are: Optimisation (going for performance) often comes at the expense of other parameters, and must be balanced against the "loss" in these areas. ... premature optimization is the root of all evil (or at least most of it) in programming.'' A good example: If you burn a week trying to optimize reflecting over an object before you have proof that it is a bottleneck you are prematurely optimizing. the premature optimization definition xkcd why root java example evil optimization - When is optimisation premature? The humorous conclusion is that if there is any doubt whether an optimization is premature, then it is premature! – Jörg W Mittag Jul 27 '16 at 0:49 attempts at efficiency actually have a strong negative impact when only make sense to do at design time. People have misused his quote all over the place, often suggesting that micro-optimizations are premature when his entire paper was advocating micro-optimizations! If a particular optimization is clear and concise, feel free to experiment with it (but do go back and check whether that optimization is effective). What he deemed "premature optimizations" were optimizations applied by people who effectively didn't know what they were doing: didn't know if the optimization was really needed, didn't measure with proper tools, maybe didn't understand the nature of their compiler or computer architecture, and most of all, were "pennywise-and-pound-foolish", meaning they overlooked the big opportunities to optimize (save millions of dollars) by trying to pinch pennies, and all while creating code they can no longer effectively debug and maintain. simply an overreaction to the abuses they see being practiced by often yield substantial savings. But it's rarely necessary to optimize the flow control & expression logic. My advice: Try to only pay the cost of optimisation when you can quantify the benefit. I am not entirely sure how to classify design choices made before that (like using well-suited data structures), but I prefer to veer towards using abstractions taht are easy to program with rather than those who are well-performing, until I am at a stage where I can start using profiling and having a correct (though frequently slow) reference implementation to compare results with. “Premature optimization is the root of all evil” is a famous saying among software developers. Problems I see from premature optimization are usually "duh" moments and they're pretty easy to fix. It pokes fun at time-wasting behavior by obsessively perfectionist coders who develop tools to analyze aspects of their software, such as performance. but when it's a question of preparing quality programs, I don't want Also note how he isn't just criticizing these "pennywise-and-pound-foolish" programmers, but also the people who react by suggesting you should always ignore small inefficiencies. Other teams include "Performance" and "Scalability" in their "done done" list, but these can lead to premature optimization. Premature optimization [xkcd.com] Re:Honestly? Don Knuth started the literate programming movement because he believed that the most important function of computer code is to communicate the programmer's intent to a human reader.Any coding practice that makes your code harder to understand in the name of performance is a premature optimization. And of course, any optimization is premature if you don't define a goal performance threshold. Optimization should never be done without metrics. “Premature optimization is the root of all evil.” That quote by Donald Knuth gets repeated a lot in programming circles. to restrict myself to tools that deny me such efficiencies [i.e., goto The point of the maxim is that, typically, optimization is convoluted and complex. While there are things where you shouldn’t compromise, such as documenting your code, is it really necessary for your script to finish in 5 minutes instead of 15? Any time you're trying to promote carefully-applied micro-optimizations as Knuth promoted above, it's good to throw in a disclaimer to discourage novices from getting too excited and blindly taking stabs at optimization, like rewriting their entire software to use goto. the premature optimization definition xkcd why root java example evil optimization - When is optimisation premature? Ken Thompson rephrased Pike's rules 3 and 4 as "When in doubt, use brute force.". Other teams include "Performance" and "Scalability" in their "done done" list, but these can lead to premature optimization. While there are things where you shouldn’t compromise, such as documenting your code, is it really necessary for your script to finish in 5 minutes instead of 15? The standard answer to these optimisation-tips questions is to profile your code and see if it's a problem first, and if it's not, then therefore your new technique is unneeded. said, they are appropriate in just a small part of a program, yet they There's something really offensive about attributing "premature optimization..." to xkcd, even as a joke. Remember: "Premature optimization is the root of all evil" (Donald Knuth). I don't think that recognized best practices are premature optimizations. In some fields, such as compilers or database design, such tools can be useful and productive (the 3% mentioned by Knuth? The flow chart has no branches. Optimization can happen at different levels of granularity, from very high-level to very low-level: Start with a good architecture, loose coupling, modularity, etc. As Knuth said, We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil. why. This means you're free to copy and share these comics (but not to sell them). The way I see it is, if you optimize something without knowing how much performance you can gain in different scenario IS a premature optimization. The point of avoiding premature optimization isn't to excuse low performance code. This work is licensed under a Creative Commons Attribution-NonCommercial 2.5 License. The title text may also be poking fun at the comic, since the comic itself may be the "system" used to determine premature optimization. More details.. Herb Sutter's C++ coding standards says to avoid Premature optimization and Premature pessimization.But I feel both is doing the same thing. For example, premature optimization could involve someone spending a lot of time and money picking out the best possible gear for a certain hobby, despite the fact that they haven’t actually tried out that hobby to make sure they enjoy it. Professor Donald Knuth, 1974. This page was last edited on 7 December 2019, at 20:30. It's only premature if you do so without first optimizing the architecture, data structures, algorithms, memory footprint, and flow-control. Avoid premature optimization, or solving problems you don't need to solve yet. Secondly, it's not obvious that user's time is more valuable than programmer's time. Optimization can prove to have been a waste of time if parts of the program are later changed or discarded, or if the optimized code is only a small part of the workload. The title text takes the joke a step further by proposing optimizing a brand new project by introducing a procedure to determine whether a possible optimization is premature - which is obviously a premature optimization. designed to provide all programmers with feedback indicating what image credit: xkcd “ Premature optimization is the root of all evil “: the famous Knuth-ism that we all know and… well, that we all know.It’s hard to go a day of reading programming blogs without someone referencing this and leaving their particular footnote on it.I suppose today I am that someone. Making a routine 10 times faster doesn't help much if that routine is only consuming 1% of the running time to begin with and it may result in more complicated and buggier code. (Multiply vs. shift, etc). So what’s my footnote? Nit-picking about whether to use a divide expression or a shift expression isn't necessarily premature optimization. Alerted to the existence of the image by Tamino. of all evil. 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