Live data from Hacker News

Claude Opus 5

anthropic.com

241–250 of 1001 posts

Re: Claude Opus 5

#241

What's the point of 150 pages description of a model that's going to be replaced in a couple months? Who even reads this? I know it's cheap to generate text with LLMs, but this is just noise at this point.

The system cards are effectively a data dump for researchers to sift through.

They're not meant for normal consumers who just want to use the model for work.

Re: Claude Opus 5

#242
Page 151 of the linked system card - did Opus 5 get nerfed to prevent it being better than Fable? The graph makes no sense. Huge decline in coding performance at effort levels higher than medium.

Re: Claude Opus 5

#243

Earlier quoted context omitted.

Is that true? Sol responses are also longer than prior models.

Anecdata: my workflow has been working on the same personal projects for months now with Codex. I cannot anymore finish my daily/weekly code with 4.8 anymore. I was dividing my work between Codex and DeepSeek. Now I barely use DeepSeek, or never because Codex quota is enough after Sol

Which plan?

Re: Claude Opus 5

#244
post #46

From the prompting guide https://platform.claude.com/docs/en/build-with-claude/prompt... >: > Claude Opus 5's default user-facing responses run longer than prior Opus models'. The benchmarks do show Opus 5 as slightly more expensive than 4.8, although the scores are much higher. This still feels like a step in the wrong direction, though, especially with OpenAI making so much progress with the efficiency of their mod…

This is part of why I switched to Grok 4.5

I don't need more powerful models, I need one that responds fast enough that my attention doesn't wander to other tasks. Grok 4.5 is so fast I can just use it in-band without swapping to other tasks.

Slower than Opus 4.8, which was already miserably slow, is indeed a step in the wrong direction.

Re: Claude Opus 5

#245
post #40

I am very confused about what the difference between Opus 5 and Fable 5 is now. What is the purpose of having two models that are so similar? The main differences I see are cost and marginal capability, according to the Anthropic-provided benchmarks.

Fable has more parameters. In practice it's not yet clear which one would be better for different usecases yet but they are more different than one being strictly better.

Re: Claude Opus 5

#247
post #41

Looking at all these releases it’s not a surprise that model routing is the fastest growing segment in AI right now. There are 10+ LLM companies, each with dozens of models of different modalities, each model with multiple size variants, then different “thinking” levels, then agentic modes, “pro” modes, a “fast” option, standard vs flex vs batch execution. And of course each end combination has a different input/outp…

Who are the customers though? Honest question, I'd like to understand it. For me, anything other than current best available SOTA for any task is unacceptable. The only routing rule I need is "the most powerful model I still have flat-priced quota available for". I mean, why settle for less?

because "less" can be so much faster?

Re: Claude Opus 5

#249
Anthropic is no longer a good model company in my mind, they are optimizing for an IPO and padding themselves on the back for being the next Aristotle. They're so far up their behind they don't realize how s**y their products are, and their research team hasn't done anything ground breaking in probably over a year other than release "scary" reports.

Re: Claude Opus 5

#250
post #168

> Opus 5’s safeguards match those of Claude Fable 5’s, with one change: it now permits source-code vulnerability discovery at all access levels. This means that the model can support defensive cybersecurity work while still blocking vulnerability discovery in compiled binaries, which is more commonly used offensively Why can't they also allow Fable to do so also? Why is source-code vulnerability discovery limited to…

Anecdotal, but I tried running a few identical biology questions through both Fable and Opus and the classifier was only rejected my queries with Fable.

This is good news. I'm doing a lot of work that Fable thinks is AI related right now (it is nothing remotely competitive to Anthropic - it's just relatively basic stuff I'm doing with learning models and so forth), yet it blocks me almost every time. I have switch to GPT-5.6-Sol for this work since it's stronger than Opus 4.8.
Post reply on HN