Ragnar {Groot Koerkamp} 🦋

As often: the SimdQuickHeap is a conceptually very simple data structure that thus can be easily optimized using SIMD, leading to pretty big speed gains.

New preprint! The SimdQuickHeap is the fastest priority queue, by far. 2x faster than a radix heap, and up to 10x faster than binary heaps. Coauthored with Johannes Breitling and Marvin Williams.

OMG! By popular demand (🤗) I'm going to speak at P99 again! This time about the SimdQuickHeap preprint that just came out: the fastest priority queue by 2x (or 10x comparing to a binary heap).

SimdQuickHeap: The QuickHeap Reconsidered Johannes Breitling, Ragnar Groot Koerkamp, Marvin Williams arxiv.org/abs/2604.25681 [𝚌𝚜.𝙳𝚂]

@valigo Getting good at GPU programming will make you a better coder on modern CPUs. A throughput-oriented mentality, while critical on GPUs, is also a way better way of coaxing better performance out of the wide, deeply-pipelined, SIMD-enabled monstrosities that are modern CPUs.

@slimjimmy @sasuke___420 5s with avx2 curiouscoding.nl/posts/1brc/

@sasuke___420 no idea?

got the 1 billion row challenge down to 20s on a single thread AVX512 is nuts

Me 15 years ago, as a PhD student: “It seems like all the interesting questions have been answered & there are no useful studies left to do.” Me now, as a funder focused on evidence-based criminal justice policy: “The biggest constraint we face is finding researchers with time to engage in important new projects.” Truly, this is the most pressing problem I have. I need an army of scholars who understand causal methods & who would jump at an opportunity to study a program or policy. Would you like to help? Email me. 🙏

Microsoft has set a goal to “eliminate every line of C and C++ from Microsoft by 2030.” What are they going to try to replace that C & C++ code with? You guessed it. Rust. And they’re going to use AI to do the “Rust re-write” at an insane speed. “Our strategy is to combine AI *and* Algorithms to rewrite Microsoft’s largest codebases. Our North Star is “1 engineer, 1 month, 1 million lines of code”. You read that right. One million lines of code, per engineer, per month. Pure insanity. This kind of decision making is common among those with a deeply held, delusional faith in the Cult of Rust. Take battle tested code, and re-write it (without a clear benefit to the end user) at a recklessly rapid rate. Then force others to adopt that rewritten code before it is ready or properly tested. All while holding a delusional belief that your new Rust code is superior in all ways, and is inherently bug free thanks to the divine nature of Rust. We learned this from a post by Galen Hunt, Distinguished Engineer at Microsoft Research. linkedin.com/posts/galenh_p…

The experience of having some muddy mess of a hundred line function with goofy "do things one way here, then do almost the same thing somewhere else, then ..." become clear and turn into a 20-line clean "computer science" type function with nice clean data structures is bliss.

If you really want to search quickly, use @curious_coding’s approach curiouscoding.nl/posts/static-s…!

@lemire I think we should have a new runtime option where stack, heap, bss, and tls are all in zones where it is guaranteed that any load of any legally addressable byte is guaranteed not to be <64 bytes from a page boundary or anything that will cause a disaster if loaded. ...

Contemplating a type system where the bit sizes required are 1, 2, 4, 8, 9, 16, 17, 32, 33, 64, 65, 128, 256, 512. Disgusting stuff, I should be ashamed of myself.

Having to pattern match Optional::None and Optional::Some(Optional::None) separately is exactly like that joke about Sartre ordering a coffee with no cream, only to be told “I’m sorry monsieur, we don’t have any cream, would you like it with no milk instead?”

It takes some mental rigour to clarify thoughts via text. Too many people are weak in thinking so they’d rather have you on a call where they can ramble off and force you to interpret their gibberish. Also, most calls are not recorded, so if you mess up, the blame is on you even though they didn’t communicate clearly.

I abhor that computer programmers still use the term “word”. > Size=2 means a word (2 bytes) Just say it’s 2-bytes. Word and Dword and Qword are stupid terms that should never be used by anyone in 2025. Just say how many bytes and be done with it!

I made reddit.com/r/bioinformati… I did this because the r/bioinformatics channel doesn't like talking about tools, especially if you wrote it yourself. If you build bioinformatic tools or want to learn more about it, join the subreddit and start posting :)