Day 16: Measure Performance Before Optimizing

Bycoliveira

Writing programs takes time, but writing correct and fast programs is even more difficult. That is why there is so much badly written software in the market. Bugs are the result of sloppy and rushed code. Programs are frequently slower than they need to be as a result.

In this situation, it sometimes seems smart to design systems that are efficient. But for many programmers, efficiency becomes an end in itself, and they end up trying to optimize code before understanding the real implications of these optimizations.

One of the most common problems is not understanding the real bottlenecks in the system. For example, when writing software for the web using standard architectures, accessing the data base is frequently the bottleneck of the system. When faced with this situation, it doesn’t matter if the code to handle string comparison is written in assembly or in Ruby, the result will be approximately the same.

Measuring Speed Up

There is an interesting result studied in computer architechture called the Ahmdal Law. This principle says that any optimization (say, getting twice the performance) applied to a part of the system that is responsible for only a small percentage of the execution time will result in a very small improvement.

For example, suppose that you improve the string handling code to be 10 times more efficient. This might give you hopes that the whole system will be a few times more efficient that it is. However, after measuring the system, you verify that the time spent on string comparison is 10% of the total time.

The result is that an operation that takes 10% of the total time now takes only 1% of the time. However, this means that the performance improvement for the whole system is just 9%.

If 9% still seems good for you, notice that I was very generous here. It is really hard to change something to be 10 times faster, unless you come up with a different algorithm. Also, the differences in percentage of usage are not commonly in the range 10 to 90%, but more frequently it is 1 to 99%. That is, most areas of your code contribute 1% or less to the running time, while bottlenecks such as network and database delays are responsible for 99% of the time.

Even for processor bound tasks this situation remains. There is probably a few small parts of your code that are responsible for 99% of the time spent in the program.

That is why measuring a system is so important. If you don’t know what is responsible for that figure of 99%, your efforts to improve the performance of the system are basicaly wasted. You should aim first at understanding what contributes to the bottlenecks in the system. Then, you can start planning on how to improve that area.

Further Reading

Read Computer Architecture: A Quantitative Approach to find everything you may want to know about Amdahl Law and how it applies to computer systems.

Similar Posts:

Similar Posts

Startups and Raising Money

Bycoliveira

It is interesting to notice that when most media outlets discuss the world of startups, they mostly address the issue of fund raising. In some way, it looks cool, especially to magazines and newspapers, to brag about millions of dollars being raised from VCs by a new company. However, what is often not said is…

Benefits of studying your own code

Bycoliveira

Lest night, I was reading an interview by Ken Thompson, the inventor of UNIX, on the book “Coders at Work“. At one point of the interview, he mentions that he considered himself a better programmer before he was 35. The main reason according to him is that he knew every line of code that he…

Five Common Mistakes in the Early Design Stage

Bycoliveira

Creating great software requires attention to several details that can make the difference between a well-designed system in one hand, and a failure in terms of features and maintainability in another. Every software engineer has a big list of elements that are necessary for a successful project and that should be part of the work…

The C Standard

Bycoliveira

One of the biggest milestones for C was the completion of the standardization process. After the creation of the standard, which involved many people from several countries, there is a single set of features that is supported across C compilers in the market. Before standardization, different vendors could, sometimes out of necessity, implement variations of…

What all programmers have in common

Bycoliveira

I have been working on software development for some time, and have seen a lot of different styles of programmers. There are the ones that clearly have a lot of talent and produce a lot of output. Others don’t have much talent, and are also not interested in improving their skills. Experience has shown that…

1,038 Comments

  4. Excellent goods from you, man. I’ve keep in mind your stuff
    previous to and you’re simply extremely magnificent.
    I really like what you’ve received right here, certainly like
    what you are stating and the way in which wherein you assert it.
    You are making it entertaining and you continue to take care of to stay it smart.

    I can’t wait to read far more from you. This is really a wonderful site.

  6. I don’t know whether it’s just me or if everyone else experiencing problems with your blog.

    It appears as though some of the written text in your content are running off
    the screen. Can somebody else please comment and let me know
    if this is happening to them as well? This might be a
    issue with my internet browser because I’ve had this
    happen previously. Many thanks

  13. Nice post. I was checking continuously this blog and I am impressed!
    Extremely useful information particularly the last part :
    ) I care for such info much. I was looking for this certain info for a long time.
    Thank you and good luck.

  15. Thanks , I’ve just been looking for information about this
    subject for a while and yours is the greatest I’ve
    came upon till now. However, what in regards to the bottom line?

    Are you sure in regards to the supply?

  16. Write more, thats all I have to say. Literally, it seems as though you relied on the
    video to make your point. You clearly know what youre talking about, why waste your intelligence on just posting videos to your site when you could be
    giving us something informative to read?

  18. I was recommended this web site by means of my cousin. I’m now not sure whether this publish is written by him
    as no one else recognize such targeted about my difficulty.
    You are wonderful! Thanks!

  20. Aw, this was an incredibly good post. Finding the time
    and actual effort to make a really good article… but what can I say… I put things off a whole lot
    and don’t seem to get anything done.

  21. Hey! I just wanted to ask if you ever have any trouble
    with hackers? My last blog (wordpress) was hacked and I ended up losing months
    of hard work due to no back up. Do you have any solutions to prevent hackers?

  22. Pokies dominate Rocket’s library and you can play a different one each half an hour till you drop.

    This way you can explore fresh titles with no actual skin in the game, which is a great incentive,
    no matter how you slice it. Make sure to read the Terms & Conditions in advance, especially those of the promotion itself, so that you can be in the
    know at all times. The wagering requirement remains 45 times, and you can also get
    100 free spins. To be able to claim the gift as yours, you’ll first need to wager it 45 times.

    While pokies are the most played and beloved section of any online casino, live games are not too far behind.

    The maximum withdrawal amount is 3,500 EUR/5,000 AUD, CAD, NZD
    for players who have made three or less deposits, regardless of their use of the welcome
    bonus. Any returns, winnings or bonuses which the player has
    gained or accrued during such time as the Duplicate Account was active may be reclaimed by us, and players undertake to return to us on demand any such
    funds which have been withdrawn from the Duplicate Account.
    We process bonus code rocket casino redemptions automatically once you
    meet the minimum deposit requirements. Verify these bonus
    code rocket casino offers are current before attempting to use them.

    This is welcomed by many, as being able to compete against other players for
    prizes and prestige is the best incentive for
    anyone with a competitive streak. Your potential wins may bring you cashback, free
    spins, deposit bonuses, and more. All in all, it’s an engaging and interactive way
    to stimulate players and help them look forward to cool rewards.
    Anyone would agree that the security of our funds and the ease with which a transaction is made are crucial when choosing an online casino to play
    at. There are over 3000 titles to choose from, all of
    which are hand-picked based on player experience.

    References:
    https://blackcoin.co/ripper-casino-bonus-codes-november-2025/

  23. It was described as Version-Less in Symantec’s press release alluding to automatic updates that always keep the software to its latest version. This
    version of Norton was released on September 5, 2012, together with the
    newest Norton AntiVirus and Norton Internet Security products.
    Also new for this version are Reputation scan, that gives the user
    clear insight of the loaded applications and files and the Safeweb for Facebook, which scans the links on the
    wall to verify their safety.
    It also provides updated versions of SONAR (version 3) and System
    insight. This version adds many new security features found
    in Norton Internet Security 2010. PC Magazine highlighted version 3.0’s inaccurate spam filter, misfiling half of valid mail
    as spam. Version 3.0 does not retain previous versions of files and
    skips files which are open by another program.
    Yes, please email for further information. Detroit Lions defensive lineman Keith Cooper
    Jr. (64) taking a photo with a disposable camera during the 2025 media day at the Meijer Performance Center on June 12, 2025 in Allen Park, Mich.
    (Katie Quinlan/Detroit Lions) Detroit Lions offensive lineman Tate Ratledge
    (69) during the 2025 media day at the Meijer Performance Center on June
    12, 2025 in Allen Park, Mich. (Katie Quinlan/Detroit Lions) Detroit
    Lions defensive lineman Ahmed Hassanein (61) signing his name during the 2025 media day at the Meijer Performance Center on June 12, 2025 in Allen Park, Mich.
    (Katie Quinlan/Detroit Lions)

    References:
    https://blackcoin.co/bay-casino-your-ultimate-guide-to-online-gaming/,complete

  24. WinSpirit Casino positions itself as an online casino aimed at Australian players, supporting AUD payments, a
    broad range of pokies and table games, and dedicated assistance for Aussie punters.
    Whether you’re playing slots or live dealer games, you can set limits to keep gaming fun and stress-free.

    Knowing your Win Spirit casino deposit and withdrawal
    limits helps you enjoy gaming smoothly.
    Win Spirit Casino is a safe and trusted platform operated by a reliable company under a valid license.
    These offers are crafted to give you a head start and maximize your fun without extra costs.

    Win Spirit Casino enhances your gaming with promo codes that unlock exciting
    rewards. The platform is designed with user convenience in mind, ensuring a smooth registration and login process.
    Getting started with Win Spirit Casino is quick and straightforward, allowing you to jump into the
    action in just a few steps.
    WinSpirit provides RTP and volatility indicators so you can pick
    games that suit your style. The site offers robust search
    capability — search by title, provider, volatility, RTP and
    popularity. WinSpirit hosts around 2,500 games from over
    50 providers, including Playson, BGaming,
    Platipus and Pragmatic Play. If you have issues
    with any transaction, contact support and reference your transaction ID.

    When you use crypto, withdrawals are usually faster;
    however network confirmations can affect the final timing.

    References:
    https://blackcoin.co/how-online-casino-vip-programs-work/

  25. They add a thrilling twist to the traditional slots experience as players vie not just for individual
    round wins but overall victory. It broadens the gaming
    experience, increases the thrill of discovery, and
    adds an extra layer of excitement to their casino journey,
    making it even more engaging and rewarding. Think of them as a gateway for new
    players to test the waters without sinking too much of their own money.

    Finally, we evaluate their bonus offerings and promotional schemes, as well as their payment methods,
    processing times, and withdrawal limits. With over 20,000 gambling machines in Australia, it can be challenging for a gamer to select one that fits best.
    Clear communication is paramount when venturing into
    online pokies in Australia. Options like AUD, USD, EUR, and crypto matter, so researching them smartly in advance
    can save the player’s experience. If you’re considering trying out
    some of the iGaming sites, it’s a good idea to learn a bit about gambling here first.

    References:
    https://blackcoin.co/find-your-best-casino-online/

  26. It’s nearly impossible to find educated people on this topic, but
    you seem like you know what you’re talking about!
    Thanks

  28. Bet Amount Total amount of your current on-table wagers For rules on specific games,
    take a look at our How To Play brochures, or
    click the Rule button on your screen. Now that you’ve set up an active Player
    Chip Account, it’s time to start playing. You can find plenty more
    information about the VIP catering experiences on Casino Canberra’s website.
    We have dined at both of these restaurants and had
    a good experience. If you require more information ask your Dealer or take a Roulette
    card from the table.
    Whether you are looking to test your luck at the
    gaming tables, host an unforgettable event, or simply enjoy a night out with friends, Casino Canberra is the place to be.

    Overall, Casino Canberra is a vibrant and exciting entertainment destination that offers something for everyone.
    The experienced events team at Casino Canberra can help plan and execute events of all types and sizes, ensuring that every
    detail is taken care of.

    References:
    https://blackcoin.co/steps-casinos-should-take-to-improve-their-cyberspace-security/

  30. Whether you’re a seasoned pro or exploring online casinos
    for the first time, Casino Mate delivers an unmatched thrill.
    Casino Mate offers a captivating gaming experience tailored to both casual players and high-stakes gamblers.
    While Casino Mate online casino clearly targets online casino players from Australia,
    the casino is also welcoming players from other countries with open arms.
    Customer support is always helpful and knowledgeable, which makes
    a huge difference when you have questions about
    games or bonuses.
    The entire site is fully optimised for mobile play,
    so there’s no need to download an app to enjoy all your favourite
    games.Whether you’re using Android or iOS, the mobile browser version runs smooth as butter.
    Players from all around the country recognize Casino Mate as a trusted and entertaining online casino platform.

    To support this, we offer a range of player protection tools designed to
    keep your gaming experience within safe and enjoyable boundaries.
    Casino Mate’s diverse range of payment options and commitment to security provides players with a trustworthy and convenient banking experience.

    Whether you are a new player or a seasoned pro, Casino
    Mate bonuses are crafted to elevate your gaming thrills.

    References:
    https://blackcoin.co/spanish-21-rules/

  31. Great beat ! I wish to apprentice whilst you amend your web site, how can i subscribe for a blog website?
    The account helped me a applicable deal. I have been tiny bit familiar of
    this your broadcast offered vivid clear concept

  35. I loved as much as you’ll receive carried out right here. The sketch is tasteful, your authored subject
    matter stylish. nonetheless, you command get bought an impatience over that you wish be delivering the
    following. unwell unquestionably come more formerly
    again as exactly the same nearly a lot often inside
    case you shield this hike.

  37. Definitely believe that which you said. Your favorite reason appeared to be on the net the simplest
    thing to be aware of. I say to you, I certainly get annoyed while people consider worries that they just don’t know
    about. You managed to hit the nail upon the top and defined out the whole thing without having side-effects , people
    could take a signal. Will probably be back to
    get more. Thanks

  38. Excellent blog here! Also your website loads up very fast!
    What web host are you using? Can I get your affiliate link to your host?

    I wish my website loaded up as fast as yours lol

  40. Howdy, i read your blog from time to time and i own a similar one and i was
    just curious if you get a lot of spam comments?
    If so how do you protect against it, any plugin or anything you can recommend?
    I get so much lately it’s driving me insane so any help is very much appreciated.

  44. Wonderful work! That is the type of information that should be shared around
    the net. Shame on the search engines for no longer positioning this put up upper!
    Come on over and talk over with my site . Thank you =)

  46. Hey! This is kind of off topic but I need some advice from an established blog.
    Is it very difficult to set up your own blog? I’m not very techincal but I can figure
    things out pretty fast. I’m thinking about creating my own but I’m not
    sure where to begin. Do you have any points or suggestions?
    Many thanks

  48. Howdy, I believe your web site could be having web browser compatibility problems.
    Whenever I take a look at your website in Safari, it looks fine however when opening in I.E., it has some overlapping issues.
    I merely wanted to provide you with a quick heads up! Aside from that, wonderful blog!

  49. Please let me know if you’re looking for a article author
    for your site. You have some really good posts and I feel I would be a good asset.
    If you ever want to take some of the load off, I’d love to write some articles for
    your blog in exchange for a link back to mine. Please
    blast me an e-mail if interested. Many thanks!

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.