[HN Gopher] LLM architecture comparison
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       LLM architecture comparison
        
       Author : mdp2021
       Score  : 345 points
       Date   : 2025-07-20 06:56 UTC (16 hours ago)
        
 (HTM) web link (magazine.sebastianraschka.com)
 (TXT) w3m dump (magazine.sebastianraschka.com)
        
       | bravesoul2 wrote:
       | This is a nice catchup for some who hasn't been keeping up like
       | me
        
       | dmezzetti wrote:
       | While all these architectures are innovative and have helped
       | improve either accuracy or speed, the same fundamental problem of
       | generating factual information still exists.
       | 
       | Retrieval Augmented Generation (RAG), Agents and other similar
       | methods help mitigate this. It will be interesting to see if
       | future architectures eventually replace these techniques.
        
         | tormeh wrote:
         | To me, the issue seems to be that we're training transformers
         | to predict text, which only forces the model to embed limited
         | amounts of logic. We'd have to find something different to
         | train models on in order for them to stop hallucinating.
        
           | lblume wrote:
           | Modern neuroscience suggests that everything the human brain
           | might be doing is basically a kind of predictive processing,
           | i.e. hallucination based on inductive biases. I do not think
           | this is the main bottleneck.
        
         | bsenftner wrote:
         | I'm still thinking about how RAG being conceptually simple and
         | easy to implement, why the foundational models have not
         | incorporated it into their base functionality? The lack of that
         | strikes me as a negative point about RAG and it's variants,
         | because if any of them worked, it would be in the models
         | directly and not need to be added afterwards.
        
           | bavell wrote:
           | RAG is a prompting technique, how could they possibly
           | incorporate it into the pre training?
        
             | maleldil wrote:
             | CoT is a prompting technique too, and it's been
             | incorporated.
        
               | bavell wrote:
               | IIUC, CoT is "incorporated" into training by just
               | providing better quality training data which steers the
               | model towards "thinking" more deeply in its responses.
               | But at the end of the day, it's still just regular pre
               | training.
               | 
               | RAG - _Retrieval_ augmented _generation_ - how can the
               | retrieval be done during training? RAG will always remain
               | external to the model. The whole point is that you can
               | augment the model by injecting relevant context into the
               | prompt at inference time, bringing your own proprietary
               | /domain-specific data.
        
               | bsenftner wrote:
               | Who says "during training"? RAG could be built into the
               | functionality of the LLM directly - give it the documents
               | you want it to incorporate, and it ingests them as a temp
               | mini-fine tune. That would work just fine.
        
               | impossiblefork wrote:
               | These things with <think> and </think> tokens are
               | actually trained using RL, so it's not like GSM8k or
               | something like that where you just train on some
               | reasoning.
               | 
               | It's actually like QuietSTaR but with a focus on a big
               | thought in the beginning and with more sophisticated RL
               | than just REINFORCE (QuietSTaR uses REINFORCE).
        
             | bsenftner wrote:
             | The same way developers incorporate it now. Why are you
             | thinking "pre-training", this is a feature of the deployed
             | model: it ingests documents and generates a mini-fine tune
             | right then.
        
           | mdp2021 wrote:
           | Why would be a proper documents-at-hand based inquiry be
           | <<simple>>.
           | 
           | Information is at paragraph #1234 of book B456; that
           | paragraph acquires special meaning in light of its
           | neighbours, its chapter, the book. Further information is in
           | other paragraphs of other books. You can possibly encode with
           | some "strong" compression information (data), but not
           | insight. The information that a query may point to can be a
           | big cloud of fuzzy concepts. What do you input, how? How big
           | should that input be? "How much" of the past reflection does
           | the Doctor use to build a judgement?
           | 
           | RAG seems simple because it has simpler cases ("What is the
           | main export of Bolivia").
        
           | rybosome wrote:
           | Well, even if we assume for a moment that we aren't talking
           | about non-public data...
           | 
           | Then RAG which serves up knowledge already in the model's
           | pretraining data is still useful, because it primes the model
           | for the specific context with which you want to engage it. I
           | maybe can see what you are saying, like why can't the model
           | just do a good job without being re-reminded? But even in
           | that sense, any intelligence, artificial or otherwise, will
           | do better given more context.
           | 
           | And that ignores the reality of data outside the model's
           | pretraining corpus, like every single business' internal
           | data.
        
         | esafak wrote:
         | The models can't tell when they shouldn't extrapolate and
         | simply need more information. Which rules can be generalized
         | and which ones can't. Why shouldn't a method `doWhizBang()`
         | exist if there methods for all sorts of other things?
         | 
         | When I was young, I once beamed that my mother was a good
         | cooker. It made perfect sense based on other verbs, but I did
         | not know that that word was already claimed by machines, and
         | humans were assigned the word _cooks_. Decades later, I had the
         | pleasure of hearing my child call me a good cooker...
        
           | lblume wrote:
           | This made me think - the fact that the underlying rule that
           | nouns e.g. representing activities such as cooking can be
           | formed from the corresponding verb via the suffix -er breaks
           | in this case is just a historical / cultural artifact of
           | languages, a type of completely unnecessary complication from
           | the machines' standpoint. Maybe LLM hallucination might also
           | partially be caused by this exception-based social modelling
           | forced via our training data into all model architectures?
        
         | ethan_smith wrote:
         | Some newer architectures like DeepSeek-V2 and Llama 3.1 have
         | actually shown significant factuality improvements through
         | architectural changes alone, including improved attention
         | mechanisms and training objectives specifically targeting
         | hallucination reduction.
        
       | Chloebaker wrote:
       | Honestly its crazy to think how far we've come since GPT-2
       | (2019), today comparing LLMs to determine their performance is
       | notoriously challenging and it feels like every 2 weeks a models
       | beats a new benchmark. I'm really glad DeepSeek was mentioned
       | here, bc the key architectural techniques it introduced in V3
       | that improved its computational efficiency and distinguish it
       | from many other LLMs was really transformational when it came
       | out.
        
       | strangescript wrote:
       | The diagrams in this article are amazing if you are somewhere in
       | between a novice and expert. Seeing all of the new models laid
       | out next to each other is fantastic.
        
       | webappguy wrote:
       | Would love to see a PT.2 w even what is rumored in top closed
       | source frontier models eg. o5, o3 Pro, o4 or 4.5, Gemini 2.5 Pro,
       | Grok 4 and Claude Opus 4
        
       | DeveloperErrata wrote:
       | This was really educational to me, felt at the perfect level of
       | abstraction to learn a lot about the specifics of LLM
       | architecture without the difficulty of parsing the original
       | papers
        
       | ajeet wrote:
       | Thank you for taking the time to detail the differences - very
       | educational and easy to read.
        
       | krackers wrote:
       | Also related https://epoch.ai/gradient-updates/how-has-deepseek-
       | improved-...
       | 
       | and some sections of https://semianalysis.com/2025/07/11/meta-
       | superintelligence-l...
        
       | TheDudeMan wrote:
       | I told Claude to read the article and propose a novel
       | architecture.
       | 
       | https://claude.ai/public/artifacts/d09f5659-847f-4b58-891a-e...
       | 
       | But I don't know if it's any good.
        
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       (page generated 2025-07-20 23:00 UTC)