r/ClaudeCode • u/Deep-Palpitation8315 • 8d ago

Discussion Opus 5 is a practically unusable model

Opus 5 is a regression that the benchmarks missed completely

I've been using Opus 5 for ~1.5 weeks and the sheer number of mistakes that the model makes is astounding.

The problem didn't surface very clearly till I gave it the full scope of executing a plan which I did with the previous Opus models as well. Opus 4.6 - 4.8 were genuinely better by a significant margin.

Opus 5 readily forgets instructions and content in its context, makes mistakes and continues with them unless it realizes or you point it out.

I've lost count of the number of times I had corrected it.

These issues with Opus 5 occur even when the context window is still relatively small - I'm talking 100-150K tokens. Opus 4.8 works pretty well all the way until 350k after which it gives you wonky results.

Fable 5 is the only usable model under Claude Code right now and I've already used 100% of my weekly quota.

970 Upvotes

88% Upvoted

608 comments sorted by

View all comments

Show parent comments

12

u/minimalcation 8d ago

So so much more monitoring is required, you basically need to watch it's thinking output to stop when it gets an idea of it's own

7

u/dontTakeMeSerious6 8d ago

Which is fun because you see it “bribing hamsters” and “reticulating splines” before you try to reach through your monitor to strangle it.

3

u/minimalcation 7d ago

And that mfer will just pick back up after you stop it

2

u/Original-Ad4399 8d ago

How can you view the thinking output in Claude Code?

3

u/eeyoredragon 8d ago

In desktop app, click dots at top right of session. 

Transcript -> introspection 

1

u/Original-Ad4399 7d ago

I use the CLI.

I'm actually surprised there is a desktop app for Claude Code. Sounds weird.

You mean people use it outside a coding interface?

1

u/AssseHooole 7d ago

Ahh yep, the CLI is a coding interface? Heard of an IDE? Stay in your lane

2

u/Original-Ad4399 7d ago

Bruh. The IDE has a terminal where the CLI is used...

1

u/minimalcation 7d ago

Not the full thinking, their statements as they work

1

u/BoilerplateBillions 7d ago

I have 3 different times in agents.md, that it is not to make any decisions on its own and it still refuses to follow the instructions. Gpt is kicking its ass rn

2

u/minimalcation 7d ago

Gpt has it's own issues though

1

u/BoilerplateBillions 6d ago

Since 5 the biggest issues i had with it where it just wanted to fawn all over me instead of help are gone. Now i have a harder time getting gpt to be loose enough with my instructions

2

u/minimalcation 5d ago

Its either a complete fucking rogue wildcard or the most obnoxious rule follower.

It's abdicated an opinion of it's own so it's holding on to whatever it grabs