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

Claude Fable 5.1 and Claude Mythos 5.1

anthropic.com

Post reply on HN
Print view View original

21–30 of 1001 posts

Re: Claude Fable 5.1 and Claude Mythos 5.1

#21

Post by freedomben »

jjice wrote: post #13
scronkfinkle wrote: post #3

Has anyone been able to get anything substantial done with Fable in the first place? I more or less had totally given up on using it since the alignment checks were so sensitive that it pretty much always threw me back to Opus.

I hear this a lot and I believe it because I've heard it from so many people, but I have never run into this in my work, and neither has anyone I know in real life. I don't use Fable for a ton of implementation work, but I use it a lot for planning, so maybe that's related to it. For planning though, I've had a very good experience with Fable and implementing with Opus.

Do your apps do anything with security? I can't hardly use Fable on our authentication service because it constantly trips up and refuses to write tests. Even just doing a security review usually triggers opus.

Re: Claude Fable 5.1 and Claude Mythos 5.1

#22

Post by eis »

I am not sure if Fable is worth it, at least with version 5 vs Opus 5. Opus beats Fable in quite a few benchmarks and at twice the cost I just haven't seen it provide noticeably better results compared to Opus. Has anyone noticed big differences? I did notice Opus maybe making more mistakes repeatedly but I don't have hard numbers on this. I hope Fable 5.1 brings noticeable improvements. I am giving it a go now on my 20x Max plan on a problem that Opus 5 has struggled for more than week now and has made very slow progress with regular regressions on the way.

Re: Claude Fable 5.1 and Claude Mythos 5.1

#23

Post by ronsor »

prettyblocks wrote: post #11
scronkfinkle wrote: post #3

Has anyone been able to get anything substantial done with Fable in the first place? I more or less had totally given up on using it since the alignment checks were so sensitive that it pretty much always threw me back to Opus.

It's probably a good model for folks doing basic software stuff, or humanities related tasks, but I work in cybersecurity on the defense/detections side and I haven't been able to use it for anything even with being in the CVP. It downgrades to Opus every time.

Fable is way too expensive for basic software stuff. Other models are more than good enough for that.

In general, if Fable isn't blocking you, there's a high chance a lower tier model would work fine.

Re: Claude Fable 5.1 and Claude Mythos 5.1

#25

Post by niteshpant »

I don't know how I feel when all the documentations are written by AI for humans.

AI to AI doc share: sure, do what you please.

AI to human: please make it legible and flowly.

example, "Every thinking block records which model produced it, and it's preserved in one direction only: Claude Fable 5.1 reads earlier models' thinking blocks, and no earlier model reads Claude Fable 5.1's." is a very Claude-isk way of writing. Choppy, long, and lacking flow.

Re: Claude Fable 5.1 and Claude Mythos 5.1

#26

Post by benjiro29 »

pookieinc wrote: post #9

"Price. Fable 5.1 will cost an estimated 25% less than Fable 5 for typical workloads, wherever usage is billed by token. This is because we’re reducing our pricing on cache reads (where the model reads inputs that have already been processed and stored). For highly agentic work, the savings will often be much larger—up to approximately 45%." Glad to see this!

I hope that this also applies to the Subscription usage. As that can then stretch out Fable usage by a lot more.

Re: Claude Fable 5.1 and Claude Mythos 5.1

#27

Post by germinalphrase »

scronkfinkle wrote: post #3

Has anyone been able to get anything substantial done with Fable in the first place? I more or less had totally given up on using it since the alignment checks were so sensitive that it pretty much always threw me back to Opus.

For a long time, no - it was completely unusually for my work that references biological information about migratory birds/other (innocuous) seasonal phenomena.

About a month or two ago, they must have tightened the black list on bio topics as it became more willing to process requests without visibly downgrading to Opus.

Re: Claude Fable 5.1 and Claude Mythos 5.1

#28

Post by Bluestein »

Unless these people start offering free, unlimited inference for a cautionary period so we can test the new model without an up-front (re-)investment, I am not touching this load-bearing pile of neuralese spew with a ten thousand token pole.-

Re: Claude Fable 5.1 and Claude Mythos 5.1

#29

Post by Avicebron »

scronkfinkle wrote: post #3

Has anyone been able to get anything substantial done with Fable in the first place? I more or less had totally given up on using it since the alignment checks were so sensitive that it pretty much always threw me back to Opus.

No, almost anything related to my job is flagged for "cyber" and my company currently has no plan to try and enroll into mythos. I'm not sure if anyone has been able to enroll solo.

It did help with some worldbuilding for my book (it wasn't incredible which gives me some hope for writers). So far opus 4.8 is the most reasonable model.

Re: Claude Fable 5.1 and Claude Mythos 5.1

#30

Post by Jcampuzano2 »

eshack94 wrote: post #14
spicypixel wrote: post #5

Yeah but haiku 5 when?

Asking the real questions. I've been wondering what the holdup on that is. Does anyone reading this have additional knowledge or insight on this?

They haven't really mentioned practically anything about Haiku in quite a while so I imagine nobody except for people inside Anthropic will have any indication.

Maybe it'll come out eventually but they don't even include it on some of their comparison benchmarks anymore, so I figure its very low priority for them.

Post reply on HN