These are archived from the now defunct su3su2u1 tumblr. Since there was some controversy over su3su2u1's identity, I'll note that I am not su3su2u1 and that hosting this material is neither an endorsement nor a sign of agreement. Harry Potter and the Methods of Rationality full review I opened up a...

These are archived from the now defunct su3su2u1 tumblr. A Roundabout Approach to Quantum Mechanics This will be the first post in what I hope will be a series that outlines some ideas from quantum mechanics. I will try to keep it light, and not overly math filled- which means I’m not really teachin...

Perf is probably the most widely used general purpose performance debugging tool on Linux. There are multiple contenders for the #2 spot, and, like perf, they're sampling profilers. Sampling profilers are great. They tend to be easy-to-use and low-overhead compared to most alternatives. However, the...

2015 was a pretty good year for Intel. Their quarterly earnings reports exceeded expectations every quarter. They continue to be the only game in town for the serious server market, which continues to grow exponentially; from the earnings reports of the two largest cloud vendors, we can see that AWS...

Have you ever mentioned something that seems totally normal to you only to be greeted by surprise? Happens to me all the time when I describe something everyone at work thinks is normal. For some reason, my conversation partner's face morphs from pleasant smile to rictus of horror. Here are a few re...

There's a meme that's been going around for a while now: you should join a startup because the money is better and the work is more technically interesting. Paul Graham says that the best way to make money is to "start or join a startup", which has been "a reliable way to get rich for hundreds of ye...

I haven't used a desktop email client in years. None of them could handle the volume of email I get without at least occasionally corrupting my mailbox. Pine, Eudora, and outlook have all corrupted my inbox, forcing me to restore from backup. How is it that desktop mail clients are less reliable tha...

Jeff Atwood, perhaps the most widely read programming blogger, has a post that makes a case against using ECC memory. My read is that his major points are: Google didn't use ECC when they built their servers in 1999 Most RAM errors are hard errors and not soft errors RAM errors are rare because hard...

In 1999, Butler Lampson gave a talk about the past and future of “computer systems research”. Here are his opinions from 1999 on "what worked". Yes Maybe No Virtual memory Parallelism Capabilities Address spaces RISC Fancy type systems Packet nets Garbage collection Functional programming Objects / ...

Hardware performance “obviously” affects software performance and affects how software is optimized. For example, the fact that caches are multiple orders of magnitude faster than RAM means that blocked array accesses give better performance than repeatedly striding through an array. Something that'...

Typical server utilization is between 10% and 50%. Google has demonstrated 90% utilization without impacting latency SLAs. Xkcd estimated that Google owns 2 million machines. If you estimate an amortized total cost of $4k per machine per year, that's $8 billion per year. With numbers like that, even...

Every once in awhile, you hear a story like “there was a case of a 1-Gbps NIC card on a machine that suddenly was transmitting only at 1 Kbps, which then caused a chain reaction upstream in such a way that the performance of the entire workload of a 100-node cluster was crawling at a snail's pace, e...

I try to avoid making predictions1. It's a no-win proposition: if you're right, hindsight bias makes it look like you're pointing out the obvious. And most predictions are wrong. Every once in a while when someone does a review of predictions from pundits, they're almost always wrong at least as muc...

I love reading postmortems. They're educational, but unlike most educational docs, they tell an entertaining story. I've spent a decent chunk of time reading postmortems at both Google and Microsoft. I haven't done any kind of formal analysis on the most common causes of bad failures (yet), but ther...

If you've followed any tech news aggregator in the past week (the week of the 24th of May, 2015), you've probably seen the story about how SourceForge is taking over admin accounts for existing projects and injecting adware in installers for packages like GIMP. For anyone not following the story, So...

TIL that Bell Labs and a whole lot of other websites block archive.org, not to mention most search engines. Turns out I have a broken website link in a GitHub repo, caused by the deletion of an old webpage. When I tried to pull the original from archive.org, I found that it's not available because B...

Boring languages are underrated. Many appear to be rated quite highly, at least if you look at market share. But even so, they're underrated. Despite the popularity of Dan McKinley's "choose boring technology" essay, boring languages are widely panned. People who use them are too (e.g., they're a ta...

Here's a conversation I keep having: Someone: Did you hear that Facebook/Google uses a giant monorepo? WTF! Me: Yeah! It's really convenient, don't you think? Someone: That's THE MOST RIDICULOUS THING I've ever heard. Don't FB and Google know what a terrible idea it is to put all your code in a sing...

Why are people so concerned with hardware power consumption nowadays? Some common answers to this question are that power is critically important for phones, tablets, and laptops and that we can put more silicon on a modern chip than we can effectively use. In 2001 Patrick Gelsinger observed that if...

It's really common to see claims that some meme is backed by “studies” or “science”. But when I look at the actual studies, it usually turns out that the data are opposed to the claim. Here are the last few instances of this that I've run across. Dunning-Kruger A pop-sci version of Dunning-Kruger, t...

I've been reading a lot about software testing, lately. Coming from a hardware background (CPUs and hardware accelerators), it's interesting how different software testing is. Bugs in software are much easier to fix, so it makes sense to spend a lot less effort spent on testing. Because less effort ...