[unicornfinder]

I'm on their pro plan and I respectfully disagree - it's genuinely excellent with GLM 5.1 so long as you remember to /compact once it hits around 100k tokens. At that point it's pretty much broken and entirely unusable, but if you keep context under about 100k it's genuinely on par with Opus for me, and in some ways it's arguably better.

[airstrike]

100k tokens it's basically nothing these days. Claude Opus 4.6M with 1M context windows is just a different ball game

[plandis]

Claude Opus can use a 1M context window but I’ve found it to degrade significantly past 250k in practice.

[marcus_holmes]

Seconded. I'm getting used to the changes that happen in the conversation now, and can work out when it's time for my little coding buddy to have a nap.

And Opus is absolutely terrible at guessing how many tokens it's used. Having that as a number that the model can access itself would be a real boon.

[airstrike]

250k is still massively more than 100k and 1M prevents it from having to compact

[wild_egg]

The Dumb Zone for Opus has always started at 80-100k tokens. The 1M token window just made the dumb zone bigger. Probably fine if the work isn't complicated but really I never want an Opus session to go much beyond 100k.

[braebo]

The cost per message increases with context while quality decreases so it’s still generally good to practice strategic context engineering. Even with cross-repo changes on enterprise systems, it’s uncommon to need more than 100k (unless I’m using playwright mcp for testing).

[bredren]

I had thought this, but my experience initially was that performance degradation began getting noticeable not long after crossing the old 250k barrier.

So, it has been convenient to not have hard stops / allow for extra but I still try to /clear at an actual 25% of the 1M anyhow.

This is in contrast to my use of the 1M opus model this past fall over the API, which seemed to perform more steadily.

[epolanski]

Quality degrades fast with context length for all models.

If you want quality you still have to compact or start new contextes often.

[syntaxing]

I’m genuinely surprised. I use copilot at work which is capped at 128K regardless of model and it’s a monorepo. Admittedly I know our code base really well so I can point towards different things quickly directly but I don’t think I ever needed compacting more than a handful in the past year. Let alone 1M tokens.

[arcanemachiner]

Personal opinions follow:

Claude Opus at 150K context starts getting dumber and dumber.

Claude Opus at 200K+ is mentally retarded. Abandon hope and start wrapping up the session.

[operatingthetan]

The context windows of these Chinese open-source subscriptions (GLM, Minimax, Kimi) is too small and I'm guessing it's because they are trying to keep them cheap to run. Fine for openclaw, not so much for coding.

[thawab]

Don’t want to disappoint you, but above 200k opus memory is like a gold fish. You need to be below 150k to get good research and implementation.

[arcanemachiner]

Oh nice, I just wrote pretty much the same comment above yours.

[kay_o]

Is manual compation absolutely mandatory ?

[jauntywundrkind]

I haven't screenshotted to alas, but it goes from being a perfectly reasonable chatty LLM, to suddenly spewing words and nonsense characters around this threshold, at least for me as a z.ai pro (mid tier) user.

For around a month the limit seemed to be a little over 60k! I was despondent!!

What's worse is that when it launched it was stable across the context window. My (wild) guess is that the model is stable but z.ai is doing something wonky with infrastructure, that they are trying to move from one context window to another or have some kv cache issues or some such, and it doesn't really work. If you fork or cancel in OpenCode there's a chance you see the issue much earlier, which feels like some other kind of hint about kv caching, maybe it not porting well between different shaped systems.

More maliciously minded, this artificial limit also gives them an artificial way to dial in system load. Just not delivering the context window the model has reduces the work of what they have to host?

But to the question: yes compaction is absolutely required. The ai can't even speak it's just a jumbled stream of words and punctuation once this hits. Is manual compaction required? One could find a way to build this into the harness, so no, it's a limitation of our tooling that our tooling doesn't work around the stated context window being (effectively) a lie.

I'd really like to see this improved! At least it's not 60-65k anymore; those were soul crushing weeks, where I felt like my treasured celebrated joyful z.ai plan was now near worthless.

There's a thread https://news.ycombinator.com/item?id=47678279 , and I have more extensive history / comments on what I've seen there.

The question is: will this reproduce on other hosts, now that glm-5.1 is released? I expect the issue is going to be z.ai specific, given what I've seen (200k works -> 60k -> 100k context windows working on glm-5.1).

[calgoo]

I have gone back to having it create a todo.md file and break it into very small tasks. Then i just loop over each task with a clear context, and it works fine. a design.md or similar also helps, but most of the time i just have that all in a README.md file. I was also suspicious around the 100k almost to the token for it to start doing loops etc.

[disiplus]

basically my expirience as well. Sometimes it can break past 100k and be ok, but mostly it breaks down.

[DeathArrow]

When using GLM 5.1 in Open Code, compaction was done automatically.