alt Hacker NewsI don't think it's care to categorize this as "a naive rewrite away from [Zig]" - Jarred has been immersed in this project for five years, got to benefit from everything he learned along the way and spent $165,000 of tokens on the most advanced coding LLM anyone has access to.
I expect if he'd spent $165,000 running Fable against the Zig version he could have got a 5% performance improvement, too.
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> and spent $165,000 of tokens on the most advanced coding LLM anyone has access to.
After having used 2 full weeks of 20x Max plan tokens on Fable over the weekend (coding all day Saturday and Sunday on a non-trivial project, tasks across full stack, mix of adding features, reviewing code, and fixing bugs), I’m confident if he’d spent $165,000 in Opus tokens the port would have gone more or less just as well (and probably for less than $165,000). Especially so with the system they set up with all the custom workflows, adversarial reviews, extensive test coverage, etc.
But I get your point is probably more about Jarred’s experience level and the high cost than the specific model used other than it being SOTA. I’m just being pedantic and feeling a bit disappointed with Fable’s real world performance after all the hype.
> I expect if he'd spent $165,000 running Fable against the Zig version he could have got a 5% performance improvement, too.
Totally agree and in fact I’m sure it could be done with significantly less cost even if they stuck with Fable instead of Opus which I’m sure could also do it.
Oh, I have no doubt that they could have extracted those gains from Zig! My point is more that, from a relatively naive line-to-line port, they were able to claim these benefits without much effort.
It's not great for Zig if you have to put in more work to end up at the same place efficiency-wise, especially for a language marketed at people who like to get the most out of their metal.
I can confirm a naive rewrite won't make things faster. I've been working on rewriting Postgres in Rust. I rewrote things function by function similar to how Jarred did. Even though the new Rust code mapped closely with the previous C code, it was 8x slower. This was due to myriad of reasons. For example naively converting a C union into a Rust enum can be slower because Rust stores a tag with the enum, while C unions do not.
I've been working on a new rewrite that's focused on beating Postgres on performance. As of this morning I got to 100% of the tests passing and have meaningful performance gains over Postgres.