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  • Havoc 7 minutes

    Nex in turn is also based on qwen so don’t think they’re too far off

  • hintymad 39 minutes

    > Every weight tensor in Rio is, to thousands of standard deviations, the same 0.6/0.4 blend of Nex and Qwen — across all 60 layers and every component of the network. Other finetunes cannot be explained as interpolations.

    I find it amazing how robust the current deep learning models are. A simple linear combination of every weight did not degrade the performance of the model, but enhanced it.

    woadwarrior01 19 minutes

    It's is a well known idea[1], although it's still surprising that something as simple, even works.

    [1]: https://arxiv.org/abs/2203.05482

    21 minutes

  • unrvl22 2 hours

    The municipality of Rio de Janeiro (via its IT company IplanRIO) released Rio-3.5-Open-397B, presented as a homegrown Qwen3.5 fine-tune that beats comparable open models on benchmarks. The linked issue argues it's actually a weighted merge of ~60% Nex-N2 Pro + ~40% Qwen3.5-397B-A17B - Nex-N2 having been released about a week earlier.

    DonsDiscountGas 57 minutes

    I didn't know model merging like that was possible. (Obviously possible from a pure software standpoint but I'm surprised it's effective)

    1 hours

    clear-octopus 1 hours

    [dead]

    Lucasoato 1 hours

    So the problem isn’t in the missing attribution to Qwen, but with the fact that they didn’t mention Nex-N2 Pro right?

    Aurornis 57 minutes

    The problem is that they claimed to have made a big achievement with their home grown post training, and they expected to receive a lot of praise for it.

    Then researchers looked at the weights and there is no post training at all.

    They are now attributing both models they merged, but their excuse for the lack of post training is to claim they accidentally uploaded the wrong files.

  • Aurornis 1 hours

    [dead]

  • diego_moita 22 minutes

    WHAT!? There are thieves in Rio de Janeiro?

    Oh, I am so SHOCKED, so SHOCKED! /s

    Explaining the joke: in Brazil, Rio de Janeiro is known as "Terra de bandido" (Gangster's Land).

    Kinda like Chicago in the 20's or Naples and Palermo in the 90s.

  • antii 1 hours

    [dead]

  • fkozlowski 1 hours

    I'm honestly surprised that they even had the inclination to attempt creating a model. I guess it's bullish that a municipal IT department had the guts to try this?

    Havoc 5 minutes

    Merges and fine tunes are within reach of individuals with some money to burn so I’m sure a muni can do it

  • 54 minutes

    51 minutes

  • alfiedotwtf 1 hours

    Wasn’t it already obvious given the awfully familiar parameter numbers?

    intoXbox 1 minutes

    That only tells what base architecture they used, but fine tuning does not increase the number of weights, it just adapts the weights to improve better on a fine tuning dataset- something they claimed they had done

  • jordz 29 minutes

    Can someone please explain or link to some information about how models are merged? Is this genuinely merging weights mathematically or some kind of distillation (presumably not if they’ve done zero training as the post suggests).

    calebkaiser 23 minutes

    This is a good starting point: https://huggingface.co/docs/peft/developer_guides/model_merg...

    But yes, in general, merging refers to techniques that directly blend the weights of different models mathematically. It had a big moment of popularity ~2 years ago, with many so-called "Frankenmodels" popping up on leaderboards.

    I tend to think of merging as belonging to the same general umbrella as things like "abliteration", or other techniques that surgically modify the weights of a model without a traditional training/tuning loop. Maxime Labonne is a great person to follow if you're interested in this general area.

  • yieldcrv 1 hours

    Didn’t the last thread about this have someone from the lab or an enthusiast in Rio saying exactly that?

    Its a fine tune of Qwen

    Not a conspiracy

    daemonologist 1 hours

    The allegation here is that it's not actually a fine-tune of Qwen, but instead an undisclosed mashup (merge) of someone else's fine-tune of Qwen and the original model. Rio subsequently said that the model was in fact a merge, that they did additional fine-tuning after the merge, and that they accidentally uploaded the base merge instead of the version with additional fine-tuning. But this seems like quite an oversight...

  • MadrasTh0rn 1 hours

    Not surprised

    nom 26 minutes

    why not?

    diego_moita 18 minutes

    It is a recurrent Brazilian meme: Rio is known in Brazil as "terra de bandido" (gangster's land).

    The majority of their politicians have ties to organized crime. There is a virtual revolving door between police and crime, where people migrate from one to the other.

    It is like Chicago in the 20s, Naples and Medelin in the 80s or Moscow and Culiacan (Sinaloa, Mexico) today.

  • AnotherGoodName 1 hours

    This is fascinating that it worked though. Can we just merge all the open weight models and get something better?

    avereveard 1 hours

    most merge improve a small subset of "feeling" benchmark (too small, too specific, or out of distribution) and tend to show degradation on actual benchmark, with especially punishing result on long chain benchmarks.

    also only work on matching architectures (i.e. finetunes/loras of the same model)

    nylonstrung 34 minutes

    If you go to Civitai this is pretty how it works in that corner of the image generation world

    Everything is using Stable Diffusion as underlying model, then most of the usage is merged of checkpoints

    _3u10 1 hours

    No, they need the same arch, but you can distill them into a single model. And yes, if you use the API directly Claude will often say it’s an open weight model (likely the ones it was distilled from)

    wds 1 hours

    I imagine it'd work the same as merging all the good-tasting foods to get an even tastier one

    dindunuf 1 hours

    that kinda worked in llama 1/2 era, not between different models but between finetunes of the same model. the briefly legendary Mythomax was IIRC a merge of 5+ tunes, some of which were merges themselves.

  • ekjhgkejhgk 1 hours

    One funny thing about incompetence is that they don't have the competence to know that their incompetence is straightforward to verify by a competent person.

    root-parent 1 hours

    You just described every single vibe coder...

    thimabi 1 hours

    I wouldn’t describe what happened here as incompetence. As a “carioca”, I am pleasantly surprised to know that the government’s IT department is involved in AI work — even without the budget to create its own models from scratch.

    arcticfox 1 hours

    This seems kind of insane though, every time I go to Rio I think of the potential of AI/technology to solve some problems and leave it even more paradisiacal... But working on their own model? Wtf? There are a million applications of existing ones there that should be followed up on instead.

    carlosjobim 1 hours

    Why would they care? They get their salaries and pensions and bonuses, and the tax payer is footing the bill.

  • AlienRobot 1 hours

    The model's webpage at https://huggingface.co/prefeitura-rio/Rio-3.5-Open-397B says it's a merge now. It previously didn't contain this paragraph:

    >The model is built via a merge of https://huggingface.co/nex-agi/Nex-N2-Pro and https://huggingface.co/Qwen/Qwen3.5-397B-A17B, proceeded by On-Policy Distillation from a stronger model. We detected an incorrect upload in the previous version, where the base merged version was upload instead of the final distilled model. We are sorry for the confusion and apologize profusely.

    Incidentally are people using Github issues as blogs now?

    jonchurch_ 46 minutes

    It wasnt framed as an issue which is the norm breakage I think you’re reacting to, as in they didnt ask that the readme be updated etc, but it is common now for folks to use a project’s issue tracker to name and shame them in a place they cant easily ignore.

    Whether that’s right, prosocial, or professional is up for debate (as well as if any single definition of etiquette can be expected in 2026 on an issue tracker).

    But surely you can see the optics reason why someone would take their complaint to the repo directly? It pressures the maintainers to respond, it allows for a pile on from the internet, and makes any decision to lock down a hostile thread into its own kind of statement.

    The maintainers should absolutely post an official response and lock the thread though, it will likely get ugly in there.

    ChoosesBarbecue 10 minutes

    But this is posted on Nex's GitHub, not on "Rio de Janeiro's" GitHub.

    i.e. this is the maintainer posting on their own GitHub Issues.

  • jrm4 1 hours

    “Well, Steve (Jobs), I think it’s more like we both had this rich neighbor named Xerox, and I broke into his house to steal the TV set, but I found out that you had already stolen it.”

    -- Bill Gates

    ckcheng 35 minutes

    What’s more funny to me is the set up to that quote:

    > Bill Gates had somehow manifested, alone, surrounded by ten Apple employees. … Steve started yelling at Bill, asking him why he violated their agreement.

    And what’s more interesting is the conclusion:

    > Apple filed a monumental copyright lawsuit against Microsoft in 1988, but they eventually lost on a technicality (the judge ruled that Apple inadvertently gave Microsoft a perpetual license to the Mac user interface in November 1985).

    Microsoft didn’t steal Apple’s GUI … Apple gave it to them.

    wunderlotus 51 minutes

    lmao i really hope this is a real quote cuz it’s a banger

    ckcheng 41 minutes

    Apparently:

    https://www.folklore.org/A_Rich_Neighbor_Named_Xerox.html

  • elzbardico 2 hours

    [flagged]

    dghlsakjg 1 hours

    This was a municipality working with a government associated IT company.

    What does it have to do with Brazilian academia?

    _3u10 1 hours

    No, typically Brazilians go to Paraguay for their education, most of their technology comes from Paraguay too.

    knuppar 1 hours

    that's just a lie lol, stop spreading misinformation

    cassiogo 1 hours

    What? Never heard of this

    stymaar 1 hours

    That sounds like nonsense, they don't even speak the same language in Brasil and Paraguay …

    guiraldelli 1 hours

    Without evidence, your comment is just bad mouthing.

    I have been involved in academia, including in Brazil, and I don't find academia there any more copycat than any other institution, including top tier ones.

    boca_honey 57 minutes

    This is very easy to prove [1][2]. Brazil has that reputation in the broarder academic world, and it's for a reason.

    [1] https://www.sciencedirect.com/science/article/abs/pii/S17511...

    [2] https://www.scielo.br/j/aabc/a/xNytDrrrHdyK4XPcHBRJZmd/?lang...

    avdelazeri 38 minutes

    One study about faculty hiring people they know, and the other about high school students cheating on assignments... What was the original claim again?

  • zinodaur 1 hours

    Oh no, someone is profiting off of their work without proper attribution!?!?

    1 hours

    clear-octopus 1 hours

    [dead]

    woadwarrior01 1 hours

    Are you new to the latest AI hype cycle? /s

    bachmeier 1 hours

    "Their work"? First you had the original content creators that did 99.99% of the work. Then you had the US companies bundle it up into a frontier LLM. Then "they" did the "work" of using the US model as a foundation for their own. So in the sense of doing 0.00001% of the actual work that went into their product, sure.

    I'd say it's more like someone forking a Linux distro, adding a few themes and fonts, and then complaining when someone else forks their distro and adds another theme.

    JoshStrobl 1 hours

    That joke really went over your head, huh...

    bwilliams18 1 hours

    That was the joke of the parent comment.

    dghlsakjg 1 hours

    That’s the joke.

    idiotsecant 1 hours

    Oof this is delete your post level I think. Sorry bud, I been there.

    harikb 1 hours

    It is only a problem if you claim it to be an independently developed OS with no attribution to base

    Aurornis 59 minutes

    This is an open weights model based on other open weights models.

    The dispute is that they released it with claims about having done some post training that improved the outputs. It was discovered that the model was not post trained like they claimed.

    The HF page now says it’s a merge of models, which wasn’t there before. They’re trying to claim they accidentally uploaded the wrong model to HF and that they’ll upload the real one soon.

    Basically, they thought they could splice two open weights models together and claim their team had accomplished some amazing post training, but they weren’t smart enough to realize that other researchers would discover that there wasn’t any post training.

    moritzwarhier 54 minutes

    Thanks for the factual clarification. This is so important when everyone already has their trigger finger on politics. Not meaning that politics are irrelevant here, see sister comment by jobim.

    But it's impossible to form a nuanced opinion when political association has a higher priority than the facts; which, again, don't look flattering for the implementers.

    iknowstuff 43 minutes

    How do they just splice two models together?

    Aurornis 36 minutes

    The Nex N2 model they merged is based on Qwen 3.5, so you can swap pieces of one into the other. They found a combination of the two that did well on some benchmarks and shipped it.

    In the early days of Llama there were a lot of experiments like this. There were even some interesting combinations of models where they stacked layers of different models together or even added more layers with interesting results.

    But announcing that you spliced two models together isn't very impressive in 2026, so they announced that they had done their own post training and outdid the big labs. They thought nobody would look close enough to notice.

    ninja3925 29 minutes

    Out of curiosity, how was it discovered? You would have to look for it to find this linear combination.

    Aurornis 11 minutes

    Check the linked GitHub issue. They explain their process.

    Scroll past the first issue to find it. It’s further down.

    internet2000 1 hours

    Attribution isn't the relevant part. Lying about your lab's capabilities is.

    functionmouse 1 hours

    leopards ate my face

    outside2344 1 hours

    But the whole game is lying and stealing isn't it?

    Planktonne 1 hours

    That's also something all the AI companies have been doing.

    dofm 1 hours

    Lying about model capability is right now the lingua franca of the cloud AI business model, almost; they yes-and each other's lies because they are in a position of needing to generate interest, including going as far as needing to trigger regulatory capture.

    (It's not news to anyone who has worked in sales-led businesses that salespeople are prone to believing the claims of other salespeople, I guess).

    adrian_b 1 hours

    I do not see anyone lying.

    The model card says:

    > Post-trained from Qwen 3.5 397B

    The model card also says that they use an inference framework based on "SwiReasoning: Switch-Thinking in Latent and Explicit for Pareto-Superior Reasoning LLMs" by Shi et al.:

    https://arxiv.org/abs/2510.05069

    So the sources seem properly attributed.

    They only claim that what they did to "Qwen 3.5 397B" has improved the LLM, including, as expected, with "strong performance in Portuguese".

    00index 1 hours

    Are you talking about the credit that was just updated an hour ago? lol

    32 minutes

    petu 1 hours

    That's attribution to Qwen team.

    There (is/was) no attribution to Nex team (they've released a model based on Qwen 3.5 397B as well).

    As per OP link Nex claims that what Rio team released (so far) is just linear interpolation of weights between Nex and OG Qwen model. With no attribution to Nex and zero signs of Rio doing any training of their own.

    carlosjobim 1 hours

    This is a pure scam on tax payer money. But what else would be expected?

    jrm4 1 hours

    Unlike the big companies who do this, which often are merely impure scams on tax payer money a little more downstream.

    philipallstar 29 minutes

    Companies that generate loads of corporation tax, income tax, and VAT revenue are the exact opposite of wastes of public money.

    carlosjobim 59 minutes

    Great, now we're defending embezzlement and fraud with public funds on HN, because we really really hate big business.

    A child caught doing something bad will cry "but my friends also did it!", is that the level of reasoning hackers want to be at?

    jrm4 55 minutes

    What part of that said "defense?"

    They can both be bad.

    blanched 52 minutes

    That seems like a bad faith read to me. Nobody is defending it, just pointing out the irony / hypocrisy. Two things can be bad, and they can be related.

    lostlogin 28 minutes

    > Great, now we're defending embezzlement

    I might be missing something, but I don’t see anyone defending the the scams.

    sdevonoes 34 minutes

    There are no hackers around here anymore. HN is mainly about business nowadays

    dmix 51 seconds

    HN has always discussed business