Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Claude Opus 5

anthropic.com

Post reply on HN
Print view View original

151–160 of 1001 posts

Re: Claude Opus 5

#151

Post by cesarvarela »

cebert wrote: 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.

Benchmarks don't reflect the difference between Opus and Fable; you need to talk to them, and eventually you'll be able to tell which one is which without looking.

I think the best proxy for this feeling is the Artificial Analysis' omniscience index. Fable has a 40 score, and Opus (4.8) has 27.

Re: Claude Opus 5

#152

Post by airstrike »

Aurornis wrote: post #128
shwaj wrote: post #97

Earlier quoted context omitted.

I like how they highlighted Opus 5 as the best for “Agentic Coding” even though the number is slightly lower than Fable. Close enough for marketing, I guess!

Using the most expensive model for all of your agentic coding work hasn’t been good practice for a long time. Not unless you have infinite money to spend. Fable is typically used for key planning, architecting, and review tasks. I think this is a case where you don’t understand the use case, not that the marketing department is making mistakes.

They cost the same if you're already at $200/mo

Re: Claude Opus 5

#153

Post by skerit »

Interesting, they finally support `system` messages anywhere in a chat conversation:

> Mid-conversation system messages are available on the Claude API, Claude in Amazon Bedrock, and Google Cloud. > > This feature is available on Claude Fable 5, Claude Mythos 5, Claude Opus 4.8, and Claude Opus 5. No beta header is required. This feature is not available on Claude Sonnet 5; use the top-level system field instead.

For nearly all models EXCEPT Sonnet 5? That is weird. How old is Sonnet 5 really?

Re: Claude Opus 5

#154

Post by arrowleaf »

postalcoder wrote: post #135

I think the most important thing here is not absolute performance. It's that organizations now have access to a Fable-ish model without Fable's 30-day data retention requirement[0]. > "Consistent with prior Opus models, Opus 5 does not have data retention requirements for general access."[1] On the Opus model release page, the reason why Fable doesn't have an ARC-AGI score is because of that retention policy[2]. 0: h…

> Updated over 2 weeks ago

I hope we get clarification on this, I can't find anything claiming that it is compatible with ZDR.

Re: Claude Opus 5

#155

Post by alvis »

postalcoder wrote: post #135

I think the most important thing here is not absolute performance. It's that organizations now have access to a Fable-ish model without Fable's 30-day data retention requirement[0]. > "Consistent with prior Opus models, Opus 5 does not have data retention requirements for general access."[1] On the Opus model release page, the reason why Fable doesn't have an ARC-AGI score is because of that retention policy[2]. 0: h…

Also the cost per task. It appears to be significantly cheaper, cheaper than sonnet!

Re: Claude Opus 5

#156

Post by tadfisher »

nightpool wrote: post #132
nerdsniper wrote: post #65

Edit: It was pointed out to me that Opus 4.8 got "21%" for successfully fully completing ~1-in-5 tasks, but also got "55.7%" for obtaining significant partial credit on some of the ~4-in-5 tasks it could not fully complete. --------------- Why does Anthropic say here that Opus 4.8 scored 55.7% on OSWorld 2.0 benchmark, but the paper published by the authors of OSWorld 2.0 say they achieved a benchmark of ~21% with Op…

You're comparing the "score percentage" (e.g. out of the total number of partial points available, how many did the agent achieve) to the "completion percentage" (how many tasks does the model score 100% on). The paper says "Claude Opus 4.8 with maximum thinking and batched tool calls scores best but still completes only 20.6% of tasks at a 54.8% partial score", which is ~the same number that Anthropic reports here (…

In what world is 55.7 the same number as 54.8?

What variance is acceptable to publish without a retraction?

Re: Claude Opus 5

#157

Post by zormino »

CaptWorld wrote: post #61
pferde wrote: post #16

Earlier quoted context omitted.

The illusion of progress and advancement, to appease shareholders, and slightly postpone the looming bubble pop.

Why are we still talking like ai is majorly used for increasing shareholder value only? Its coding performance is top notch and quality is increasing at a rapid pace. It wasn't even half this good a year back. It even is useful for a subset of math problems.

People don't seem to be able to reconcile the fact that there is likely an overbuild and overspend on AI that may be inflating a bubble, and that AI is actually incredibly useful and getting really really good for certain tasks. Both camps are right, except for when they say the other is wrong.

Re: Claude Opus 5

#158

Post by adam_arthur »

ActivePattern wrote: post #144
shwaj wrote: post #97

Earlier quoted context omitted.

I like how they highlighted Opus 5 as the best for “Agentic Coding” even though the number is slightly lower than Fable. Close enough for marketing, I guess!

I think you're being overly cynical here. First, I don't see any claim that is the world's best model for agentic coding. Second, it is absolutely the best model in terms of coding performance vs. dollar, and it's raw performance seems very close to the frontier.

GPT 5.6 is far more token efficient at most tasks with similar performance. Especially so for Opus 4.8, still to be seen with Opus 5.

Where are you getting cheaper per dollar?

Re: Claude Opus 5

#159

Post by HyperL0gi »

impulser_ wrote: post #91
HyperL0gi wrote: post #55

Isn’t it just hilarious that a model that seemed so superior to Fable but didn't get doomsay marketing from Anthropic got released without any issues? In theory, this was supposed to be AGI level according to Anthropic, yet here we are, just a normal Friday.

Go read the safeguards section in the report and you will realize why that is. These models are heavily as safeguarded and that was the initial reason why they said they couldn't and haven't released Mythos because that model is the one without the safeguards. OpenAI is did the same thing when they announced a model without safeguards broken into HuggingFace servers.

Yes, this makes a lot of sense, but it’s just very amusing to see. 2 months ago, the world was about to end, now not so much.

Re: Claude Opus 5

#160

Post by manojlds »

shwaj wrote: post #97
rb2e wrote: post #17

https://www.anthropic.com/news/claude-opus-5 - A blog post for those not wanting to go through a 190ish page pdf

I like how they highlighted Opus 5 as the best for “Agentic Coding” even though the number is slightly lower than Fable. Close enough for marketing, I guess!

Which numbers are you seeing? It does show that it's better than Fable 5 in most things related to coding?
Post reply on HN