Feels like the comments are fighting of prepaid influencers.
Composer: Building a fast frontier model with RL
151–160 of 169 posts
Re: Composer: Building a fast frontier model with RL
#152Earlier quoted context omitted.
This is just a completely different use of LLMs and has little to do with working at a real business with a live site and users. Cursor is great when you want to gain understanding of an issue quickly, or resolve something clear and specific quickly. I'm not against YOLO vibe coding, but being against tab completion is just insane to me. At the end of the day, LLMs help you achieve goals quicker. You still need to kn…
Some of these projects are at a "real business with a live site and users". Two of the current ones are. And it's not remotely "YOLO vibe coding". All the code gets reviewed, and tested thoroughly, and they are worked to specs, and gated by test suites. What I don't do is babysit the LLM until it's code passes both the test suite and automated review stages, because it's a waste of time. Others of these projects are…
To be clear, Claude probably also introduced the bugs?
I tried to use an appropriate emoji to express the joking nature of this comment, but HN silently filtered it out, so pretend you see a grinning face.
Re: Composer: Building a fast frontier model with RL
#153The metrics in the post seem quite abstract. Does anyone know the detailed metrics of this mysterious model? Was it fine-tuned from open models or trained from scratch?
Re: Composer: Building a fast frontier model with RL
#154Earlier quoted context omitted.
> "Best Frontier" includes GPT-5 and Sonnet 4.5, which both outperform Composer.
>> "Best Frontier" includes GPT-5 and Sonnet 4.5, which both outperform Composer. Looking at the graph, it would appear there's an implicit "today" in that statement, as they do appear poised to equal or surpass Sonnet 4.5 on that same benchmark in the near future.
What Cursor is really emphasizing here is speed — they’re claiming it runs about four times faster than GPT-5/Sonnet, while still offering roughly the same level of performance.
Re: Composer: Building a fast frontier model with RL
#155The lack of transparency here is wild. They aggregate the scores of the models they test against, which obscures the performance. They only release results on their own internal benchmark that they won't release. They talk about RL training but they don't discuss anything else about how the model was trained, including if they did their own pre-training or fine-tuned an existing model. I'm skeptical of basically ever…
Disagree. The ultimate bar which is easily measurable, do users find value in it. Benchmarks are mostly meaningless especially in my opinion where cursor shines which is the tool chain. You can go try composer yourself today and see if it’s valuable to you.
Re: Composer: Building a fast frontier model with RL
#156Earlier quoted context omitted.
> Sonnet 4.5 quality is about as low as I'm willing to go. literally a 30 day old model and you've moved the "low" goalpost all the way there haha. funny how humans work
Yup - just like sibling comment said - my "low bar" is going to be whatever the best model is that isn't unreasonably costly/expensive. Speed of model just isn't the bottleneck for me. Before it I used Opus 4.1, and before that Opus 4.0 and before that Sonnet 4.0 - which each have been getting slightly better. It's not like Sonnet 4.5 is some crazy step function improvement (but the speed over Opus is definitely nice…
I think Opus 4.1 is still much better than Sonnet 4.5
Re: Composer: Building a fast frontier model with RL
#157The lack of transparency here is wild. They aggregate the scores of the models they test against, which obscures the performance. They only release results on their own internal benchmark that they won't release. They talk about RL training but they don't discuss anything else about how the model was trained, including if they did their own pre-training or fine-tuned an existing model. I'm skeptical of basically ever…
Disagree. The ultimate bar which is easily measurable, do users find value in it. Benchmarks are mostly meaningless especially in my opinion where cursor shines which is the tool chain. You can go try composer yourself today and see if it’s valuable to you.
Isn't that up to the reader/visitor/user to decide? As it stands right now, Cursor are publishing results they won't say how they got them, and compares them against aggregate scores we don't know the true results of, and you're saying "it doesn't matter, the tool is better anyways".
Then why publish the obscured benchmarks in the first place then?
Re: Composer: Building a fast frontier model with RL
#158I wish it was easy to find out how much it costs relative to Claude :)
As a stealth model, it was priced as $1.25M in / $10M out Right now, it seems free when you are a Cursor Pro user, but I'd love more clarity on how much it will cost (I can't believe it'll be unlimited usage for subscribers)
A bit late but it's actually not free. You can see it on their models page. It's similarly priced to GPT-5 and Gemini 2.5 Pro.
Re: Composer: Building a fast frontier model with RL
#159Maybe I'm an outlier but Sonnet 4.5 quality is about as low as I'm willing to go. It's generation speed is not the problem or the time sink. It's wrestling with it to get the right output. --- And just to clarify as maybe I misunderstood again but people are comparing cursor to Claude Code and codex etc here- isn't this whole article all cursor just using different models?
> Sonnet 4.5 quality is about as low as I'm willing to go. literally a 30 day old model and you've moved the "low" goalpost all the way there haha. funny how humans work
Not sure about parent, but my current bar is set by GPT-5 high in codex cli. Sonnet 4.5 doesn't quite get there in many of the use cases that are important to me. I still use sonnet for most less intelligence phases and tasks (until I get crunched by rate limits). But when it comes to writing the final coding prompt and the final verification prompt and executing a coder or a verifier that will execute and verify well it's GPT 5 high all the way. Even if sonnet is better at tool calling, GPT 5 High is just smarter and has better coding/engineering judgement and that difference is important to me. So I very much get the sentiment of not going below sonnet intelligence 4.5 for coding. It's where I draw the line too.
Re: Composer: Building a fast frontier model with RL
#160Cursor has the best Tab model, and I feel like their lead there has kept growing - they're doing some really cool things there. https://cursor.com/blog/tab-rl I wonder how much the methods/systems/data transfer, if they can pull off the same with their agentic coding model that would be exciting.
I agree, I tried to switch to Zed this week, and I prefer it in all respects, but the tab model is much worse, and it made me switch back. I never imagined I would care so much about a feature I felt was secondary.
I actually find myself using the agent mode less now, I like keeping code lean by hand and avoid technical debt. But I do use the tab completions constantly and they are fantastic now ever since they can jump around the file.