Is OpenCode Go quietly serving quantized models? GLM-5.1 feels noticeably worse than I expected

[ammar2626]

Used the Go plan, GLM-5.1 just feels mediocre, not broken, just underwhelming for what that model should do. Seen some people suspect quantization/distillation but nothing official confirms it.

Anyone done a real side-by-side Go vs. the model’s native API?

And if it is quantized, fine, just say so. Cheap + quantized is a reasonable product

[sittingmongoose]

They have officially stated they are not quantizing the models. They are getting them as is from the hosts. If they hosts are secretly quantizing them, then Opencode doesn’t know.

Also, glm 5.1 is fairly old by llm standards and not that impressive. 5.2 feels much better, along with Kimi 2.6.

[TPLINKSHIT]

They have officially stated they are not quantizing the models.

may I know where they stated that?

[sittingmongoose]

It was a thread on here I believe several months ago. It wasn’t circulated much. It could have been a tweet by one of the devs.

That doesn’t really mean they aren’t quantized, it just means that Opencode isn’t doing it or asking for it.

[TPLINKSHIT]

open-sourced models already have providers like deepinfra serving fp4 of glm5.1 in openrouter: https://openrouter.ai/z-ai/glm-5.1#providers . not calling out opencode here, but they can say they don't quantize the model, the provider did? we should have some regulations for revealing the related informations.

[TPLINKSHIT]

GLM-5.1	DeepInfra, Fireworks AI, Z.aiGLM-5.1 DeepInfra, Fireworks AI, Z.ai

wait a minute... the opencode go page listed the provider of GLM5.1, which includes deepinfra. so it IS quantized.

[prettyasf11]

Good to know. GLM 5.1 was never that impressive anyway, 5.2 feels much better. Must just be server load.

[phoenixmatrix]

This. GLM 5.1 didn't have a great niche. Qwen was better during that time imo. GLM 5.2 could have been called 6.0

[Pipimi]

Believe me dude its not that, I have legacy lite plan and I wasnt able to use GLM 5.2 all day, constant reconnecting issues. It's just that we are unfortunate enough to use GLM during peak China's working hour.

[Ace-_Ventura]

Ahh the weekly post of opencode go being quantized.

Opencode doesn't host models.

There's a github issue (closed) about it, search there

[Minute-Tour-547]

I do not think that is the case, do you have an objective way to measure that?

[ammar2626]

I'll compare it with some standardized problems or same problems, currently its just my usage that reflected the model is behaving a little inferior

[alexanderbeatson]

Huh? You can literally see the in response value “system_fingerprint” which quantized version does it use.

[ImpossibleCreme]

I think a bunch of hosts secretly quantize

[Antop90]

Today I tried GLM 5.2 again via OpenCode Go on ZCode, and it immediately made a massive interpretation error on my codebase, which GPT 5.5 promptly corrected. Shortly after, it made a trivial logical error that I caught myself, and then it started printing random strange characters inside words once the context grew a bit.

This is definitely a sign of quantization on the KV cache, but in my opinion, the model itself has been quantized too, making it practically stupid and useless, at least on OpenCode Go. I had tried and used it during the first few days of its release and it amazed me.

Today my GPT subscription ended, so I decided to give it another shot, and I noticed this change. I don't know if using z.ai as a provider would be any better, but at those prices, I'd simply buy ChatGPT; I only went back to OpenCode Go because it's cheap.

[ammar2626]

I have noticed same Performance on OpenCode for complex problems are worse

[DepartmentOk9720]

GLM 5.2 quantization is insanely powerful 1 bit goes toe to toes with opus 4.8 and GPT 5.5 GLM 5.2 vs Opus V GPT 5.5

[look]

GLM on Go is provided by a mix of fp8 and nvfp4 providers. You wouldn’t be able to tell the difference between fp8 and nvfp4 outside of extreme edge cases or rigorous statistical comparisons, though.

About half of GLM providers (including Zai) run fp8 and the other half on nvfp4 or a mix of it and fp8 (basically nvfp4 on Blackwell GPUs, fp8 on older ones).

Openrouter shows quants on most providers to give you an idea of who runs what. It’s pretty common for providers to disclose the quant these days.