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Comment by jabart | Hacker News Reader

The .NET community started their own version and included some other languages. I think I saw Rust at 1.4s or so but was disqualified because it was optimized to that dataset (no idea how they determined that). Someone wrote some SIMD code for c# and was like 1s. Shaving some milliseconds between c#, c++, and rust in the final end for 1 billion rows is still impressive.

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I maintain cross-language results. There will be a huge update soon, including AWS metal instances running on many combinations of cores/HT-threads.

What you mention from Rust is this: https://github.com/RagnarGrootKoerkamp/1brc/ The author says himself that his solution is not compliant in the readme.

So far the top place is not clear. .NET with noahfalk, C/C++ from lehuyduc, dzaima and austindonisan require more tests. The last looks the fastest so far on the default dataset, but has issues.

Here is my blog post with details: https://hotforknowledge.com/2024/01/13/1brc-in-dotnet-among-...

I think you're talking about a Rust solution that works by reading a small prefix of the input and generating a perfect hash with no handling for misses. So it will be wrong for any input that contains station names that do not occur in that prefix.

> Someone wrote some SIMD code for c# and was like 1s.

CLR performance can be considered nondeterministic given it JITs and performs profile-guided-optimizations - unless you go with AOT, but there's still going to be an initialization delay, and differences in cold vs. warm. vs hot-start scenarios. In order to be fair to all languages/platforms/runtimes involved, how is that managed?

The answers to these questions are at the links posted in a sibling comment a couple of hours ago.

..which we then proceed to run in a container running on a VM on a random machine in the cloud :-)

Do you have a link to the .NET community work?

https://github.com/praeclarum/1brc

That's on a machine with more cores. The "baseline" 04:49.679 Java solution runs in 03:17.70 on that machine.

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