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GLM 5.2 vs. Opus

65 points1 hourtechstackups.com
cultofmetatron30 minutes ago

I seriously dont' know all this big hullabaloo about one shot prompting.

by definition, a single prompt wont' constitute the complexity of a software project. ergo, what you'll get is a series of assumptions made by the model based on preexisting code in its training corpus.

I'd rather see a coding agent that can follow steps in a plan file to a T while following guardrails and adhering to the proper coding conventions in the human reviewed spec.

Id rather see performance in agent loops against human defined objectives where it can be verified to stick to defined guardrails and continue without drift till its objectives are complete.

I'd also like to see it identify bugs and potential performance increases by identifying existing code and suggesting refactors based on context it can pickup about the particular use case you are trying to create.

These are way more valuable metrics than "hey build X"

epolanski23 minutes ago

Yet this is how virtually everybody is benchmarking and fine tuning.

Since Opus 4.6 I've seen later Anthropic models being more and more capable on one hand, but also less useful on multi turn open tasks.

It feels like with each model they are more and more prone to go "their own way" and jump into the implementation as soon as they can.

I can't but blame it on benchmarks and fine tuning around prompt-to-solution work.

meander_water53 minutes ago

> So we ran it head-to-head against Claude Opus 4.8: same one-shot prompt, build a 3D platformer in raw WebGL from scratch

Running a single one-shot prompt is not a benchmark, not is it representative of any sort of real-world usage.

Most agent usage is collaborative so you need to test things like reliability (when I delegate a task, does it complete it without making up test results for e.g.) and steerability (does it obey my instructions or does it just do what it thinks is best).

jameswhitford49 minutes ago

Hi, I am the author, I completely agree! I set out to run a vibe test on this one, not a benchmark, the real benchmarks are listed. My test shows what the models can do when both tasked with a long-running, technically difficult, one-shot task.

I think your test you describe (collaborative, task delegation, task completion, TTD, steerability) is a great format for a future test that I will definitely try out.

meander_water34 minutes ago

Thanks, I didn't mean to be brusque, but I have seen a lot of these vibe tests lately that come to grand conclusions like "X model is better than Y" from the result of a single prompt.

Appreciate you sharing the results of your tests though!

wongarsu30 minutes ago

Tbf, most of the "real benchmarks" have issues that are just as bad. Assessing LLM performance is just hard

esperent37 minutes ago

On the other hand, I did just leave my pi agent running GPT 5.5 overnight on a clearly defined, long running task. It's been running about 10 hours now and it's mostly done. So this kind of use case is also valid.

Thinking about it, I would say that the majority of agentic work I do, by a long shot, is subagents which are launched from the main session, using a prompt of its choosing. Those could be considered short versions of these fully autonomous tasks.

ritzaco51 minutes ago

sure that's why we look at a mix of formal benchmarks, one longer analysis of a side-by-side, and various other people who we trust to form an opinion, all covered in the article - not intended to be a formal benchmark, there are enough of those.

patates42 minutes ago

Then maybe you should add that caveat emptor to the article?

You make a very strong claim at the end that the hype is mostly real, and making it clear to what extent your claim holds should help the reader.

ulrikrasmussen19 minutes ago

> Through an API it costs a fraction of Opus, and you can run it yourself for free if you have the hardware.

I haven't been keeping up on hardware costs for state of the art LLM inference, but this remark made me ask myself how many readers of the article would actually be able to run this model on hardware they own. How much would it cost to acquire such a setup?

jack_pp16 minutes ago

This framing local LLMs as free is stupid. Basically pay 100+ months worth of API costs up front isn't free in the slightest

zkmon18 minutes ago

Cost difference matters most as cost optimization is the whole point of AI. Time difference (30 min vs 1 hr) is not a deal-breaker. The small precision gap on the first iteration does not matter for 99% of the work that happens in real world.

xlii46 minutes ago

I've been checking out GLM 5.2 on some projects and few thoughts on it:

- it takes it sweet time to get code rolling, not the fastest model by any means

- it strays a lot during discovery/planning but then corrects

- it's not steering friendly, as it hallucinates things that it doesn't follow later on

- its output is quite good

A sample use case: I was optimizing rendering on Swift+Zig codebase. It chocked on 5k data entries.

GLM 5.2 spent 20 minutes building the benchmarks and getting data out, which made me frustrated so I blocked non-editing tool access and went AFK, after approx. 30 minutes I found that it used already-made benchmarks and some "conclusions" to optimize 3 choke points. Output pointed that it couldn't validate suspicions and asked for more data.

Implementation worked well, it was idiomatic and non-intrusive. I would even say that it was more idiomatic than GPT 5.5 effects on same repo.

I would opt in in using it more BUT GPT usually completes same requests 5x faster.

GLM 5.2 was spark for preparing and running inside isolated containers with JJ workspaces (so that multiple can be ran in parallel).

Imanari25 minutes ago

This mirrors my experience. I have been using it in Pi. It is smart and output is good but it is not efficient in getting there.

speedgoose20 minutes ago

While this is interesting, one single sample with different coding harness is not very scientific.

david_shi25 minutes ago

> GLM-5.2 cost a fraction as much. Opus finished in half the time and shipped a cleaner game.

Off topic, but does anyone else instantly pick up on LLMisms like this? It seems like all the models have converged on this style of writing, and improvements aren't really changing it.

speedgoose21 minutes ago

I think a bunch of real humans started to adopt the LLMs writing style.

leumon24 minutes ago

I've seen glm 5.2 struggle writing simple compilable c code. It might be good at web, but it's world knowledge is limited due to the small model size, making it's use quite limited in my opinion.

Aozora729 minutes ago

I used GLM 5.0/5.1/5.2 for some projects, and for me, the area in which they lag behind frontier models the most are user interfaces. They get really close to Opus when it comes to pure algorithms, but when I need something like web application or a mobile app that looks and works well, they are very noticeably worse than even Sonnet.

jkwang44 minutes ago

GLM-5.2 is quietly becoming the most interesting open model release this year. The coding benchmarks are surprisingly close to frontier models at a fraction of the inference cost.

epolanski17 minutes ago

To me DS 4 is still the most interesting due to much lower costs. Also DS 4 training isn't done yet.

From my Opus vs DS 4 Pro personal benchmarks, 16 different real-life work tasks, DS 4 has performed as well as Opus 4.8 high overall but with few drawbacks:

- on the 16 tasks, one needed several prompts to be steered back into the topic

- its review capabilities seem worse

- DS4 had the cleanly better solution in 3 cases out of 16, with Opus "only" doing cleanly better 2 times out of 16. But still, I want to emphasize, is the worst case scenarios that imho matter the most, not the best ones, and on that front Opus outperformed.

That being said I spent less than 2$ of API working 4 days, which is more or less what I would've spent with Anthropic APIs for less than one task.

IronWolve38 minutes ago

Having issues with coding a render for good looking realistic smoke coming off burning incense, opus 4.8 & gpt-5.5 both have code issues, glm-5.2 did it. Amazing.

The real time 3d fluid dynamics appear to be the tricky part, I wish I still had opus access, would love to see if it can do it.

linzhangrun30 minutes ago

Just that their Coding Plan is too hard to get. I've been trying to grab it for a week and still can't get it

greyman47 minutes ago

>On output tokens, GLM-5.2 is less than a fifth the price of Opus.

Opus is most expensive model in pay as you go model, but IMO fair comparison should include subscription price as well. For example when one has $100 Claude Max and use it up through the month, it might not be more expensive than GLM, or at least not 5x.

Aozora735 minutes ago

There is, for example, OpenCode Go subscription, which for $10 a month gives you a decently generous quota of GLM-5.2, among other models.

And z.ai themselves also have subscriptions.

jameswhitford43 minutes ago

Yes this is true. This test was run on a $20 pro Claude subscription. I would definitely love to try use both models on the highest plans for a whole month and compare the two, great format for a future head-to-head comparison.

buster41 minutes ago

Is it fair when the one is heavily subsidized and the other one is not?

I think it's most fair to compare the plain token pricing that is used by everyone.

esperent35 minutes ago

> Is it fair when the one is heavily subsidized

As a consumer, yes, it's totally fair. All that matters to me is the price I pay at the pump, not whether that price is "real" or not.

lithiumii44 minutes ago

GLM has subscription plans too.

linzhangrun29 minutes ago

Out of stock, unavailable

joshrw40 minutes ago

Chinese models optimize for benchmarks and do poorly in real-world tasks

epolanski16 minutes ago

Not my experience at all, I have written about comparing DS4 vs Opus 4.8 on 16 real life work tasks on multiple posts.

Also, every single lab does RL on benchmarks, which is why Opus 4.6 was the last truly great assistant, after it, all models tend to drift into implementation asap.