Top all-time · #2723
Colin Scott
Personal blog · colin-scott.github.io/blogsystemsprogramming
Colin Scott writes site_title, a personal blog at colin-scott.github.io about systems and programming. Since 2015, 28 different Hacker News readers have linked it 31 times, most often “How “latency numbers everybody should know” decreased from 1990–2020”. The last post was in 2017, but the archive is still widely read.
Too few sampled comments (19) to say how often HN recommends it.?
Why HN links it
HN readers link Colin Scott's interactive 'Latency Numbers Every Programmer Should Know' pages, which chart computer latency figures over the years. Commenters value it for showing change over time.
Summarised by Claude from a sample of 19 HN comments that link here. Each comment is marked recommending, critical or neutral (citing without judging); how this works.
Thoughts on distributed systems
Most-linked posts?
- How “latency numbers everybody should know” decreased from 1990–202021 people · 23 mentions · first linked 2020-01-28
- Fuzzing Raft for Fun and Publication2 people · 2 mentions · first linked 2015-10-07
- Technologies for Testing Distributed Systems2 people · 2 mentions · first linked 2016-03-07
What Hacker News says?
it is easy to assume most programmers today know roughly how long things take since this has existed in various forms since Jeff/Peter first published it: https://colin-scott.github.io/personal_website/research/inte... (This version is more useful since it shows change over time)
Comment linking /personal_website/research/interactive_latency.html
on “Searchcode.com’s SQLite database is probably 6 terabytes bigger than yours”Submitted How “latency numbers everybody should know” decreased from 1990–2020 as a story · 611 points
HN discussionI really found this valuable, particularly the slide at the top that enables you to visualize low level latency times (Jeff Dean numbers) over the years. tl;dr: not much has changed in the processor hardware numbers since 2012. So everything right of the processor is where the action is. And sounds like people are starting to actually make progress. https://colin-scott.github.io/personal_website/research/inte...
Comment linking /personal_website/research/interactive_latency.html
on “Computer Latency: 1977-2017”Submitted Fuzzing Raft for Fun and Publication as a story · 64 points
HN discussionThe original source linked from this post [0] is using models that assume exponential growth of bandwidths over time (see the JavaScript at the bottom of the page): this is fun, but these figures are real things that can be measured, so I think it’s very misleading for the site in this link to present them without explaining they’re basically made up. The 1Gb network latency figure on this post is complete nonsense…
Comment linking /personal_website/research/interactive_latency.html
on “Latency numbers every programmer should know”Submitted Fuzzing Raft for Fun and Publication as a story · 19 points
HN discussionThis figure quoted on this website is completely wrong: the serialisation delay of 1KiB on a 1Gb link is much higher than that, it’s actually closer to 10us. This is a transcription error from the source data, which as it turns out is based on a rough exponential model rather than real data, but first let’s consider the original claim: If there’s a buffer on the send side, then assuming the buffer has enough space,…
Comment linking /personal_website/research/interactive_latency.html
on “Latency numbers every programmer should know”Submitted Interactive Latency Numbers as a story · 17 points
HN discussionThe original is honestly better: https://colin-scott.github.io/personal_website/research/inte...
Comment linking /personal_website/research/interactive_latency.html
on “Latency numbers every programmer should know”Submitted Latency Numbers Every Programmer Should Know as a story · 2 points
HN discussionhttps://colin-scott.github.io/personal_website/research/inte...
Comment linking /personal_website/research/interactive_latency.html
on “AWS costs every programmer should know (2019)”Submitted Do Toll-Free Phones Violate Net Neutrality? A Blueprint for Toll-Free Cell Data as a story · 2 points
HN discussionPer year version https://colin-scott.github.io/personal_website/research/inte...
Comment linking /personal_website/research/interactive_latency.html
on “Latency Numbers Every Programmer Should Know (2012)”Submitted Technologies for Testing Distributed Systems as a story · 2 points
HN discussionThis gets posted here frequently - I submitted it a year ago - but imo that's not a problem because it's insightful and useful. Should have a (2012) tag though. I also ran across this version that updates the numbers to 2020 values: https://colin-scott.github.io/personal_website/research/inte... edit: it appears they're just estimating for a given time above, not measuring...
Comment linking /personal_website/research/interactive_latency.html
on “Latency Numbers Every Programmer Should Know (2012)”Submitted Technologies for Testing Distributed Systems, Part I as a story · 2 points
HN discussionThat’s true, but also networks can be fast. https://colin-scott.github.io/personal_website/research/inte... It can be faster to read over the network than to read from a hard drive.
Comment linking /personal_website/research/interactive_latency.html
on “Best practices can slow your application down”Submitted Fuzzing Raft for Fun and Publication as a story · 2 points
HN discussionI don't know if the book goes into this, but one thing I've noticed about brilliant software people like Jeff Dean or Martin Thompson is that they appear to love doing simple "back-of-the-envelope calculations" (and lots of them). They can iterate designs rapidly in their head or on paper, evaluate the cost or value of a design, know when a design has promise or when it won't work, and where the bottlenecks or low-h…
Comment linking /personal_website/research/interactive_latency.html
on “Habits of Expert Software Designers (2019)”Submitted Latency Numbers Every Programmer Should Know (Over Time) as a story · 1 points
HN discussionObligatory link to Latency numbers every programmer should know. https://colin-scott.github.io/personal_website/research/inte...
Comment linking /personal_website/research/interactive_latency.html
on “The Uselessness of "Fast" and "Slow" in Programming”Submitted 7 Ways to Handle Concurrency in Distributed Systems as a story · 1 points
HN discussion> Reading a file takes a couple hundred nanoseconds on a modern SSD. According to "Latency Numbers Every Programmer Should Know (2020)" [1] reading even a single page from a modern SSD takes over 10 microseconds. [1] https://colin-scott.github.io/personal_website/research/inte...
Comment linking /personal_website/research/interactive_latency.html
on “How we built JSR”Submitted Fuzzing Raft for Fun and Publication as a story · 1 points
HN discussionSo you know the latency numbers that every programmer should know? (I hope you do: https://colin-scott.github.io/personal_website/research/inte... ) Is there an equivalent for software org spend? Obviously it couldn't be as principled as the above but if you look at engineering at StackOverflow and their compute / requests ratio it's orders of magnitude better than companies I've worked at. I just want numbers in sp…
Comment linking /personal_website/research/interactive_latency.html
on “What the Goddamn Hell Is Going on in the Tech Industry? – Ludicity”While the numbers are changing, there are still 2-3 orders of magnitude between RAM and SSD latency: https://colin-scott.github.io/personal_website/research/inte...
Comment linking /personal_website/research/interactive_latency.html
on “Sussman Explains the End of SICP”No, because at 8 nines (99.999999%) you're responsible for the 310ms of downtime per year, aka ping time. 100% uptime would be all of Slack running in memory. See "Latency Numbers Every Programmer Should Know" https://colin-scott.github.io/personal_website/research/inte...
Comment linking /personal_website/research/interactive_latency.html
on “Slack said it had 100% uptime. Did it really?”It’s just a copy of https://colin-scott.github.io/personal_website/research/inte... ?
Comment linking /personal_website/research/interactive_latency.html
on “Latency numbers every programmer should know”What-ifs really need to be dated. Some of those assumptions are enough to date it; 160tb/kg is kind of laughable now, when talking about micro SD cards. Reasonably guessable using https://colin-scott.github.io/personal_website/research/inte...
Comment linking /personal_website/research/interactive_latency.html
on “I raced a homing pigeon against the Internet [video]”I like the interactive version: https://colin-scott.github.io/personal_website/research/inte...
Comment linking /personal_website/research/interactive_latency.html
on “Numbers every LLM Developer should know”
