Show HN: How I topped the HuggingFace open LLM leaderboard on two gaming GPUs

dnhkng.github.io

384 points by dnhkng 20 hours ago


I found that duplicating a specific block of 7 middle layers in Qwen2-72B, without modifying any weights, improved performance across all Open LLM Leaderboard benchmarks and took #1. As of 2026, the top 4 models on that leaderboard are still descendants.

The weird finding: single-layer duplication does nothing. Too few layers, nothing. Too many, it gets worse. Only circuit-sized blocks of ~7 layers work. This suggests pretraining carves out discrete functional circuits in the layer stack that only work when preserved whole.

The whole thing was developed on 2x RTX 4090s in my basement. I'm now running current models (GLM-4.7, Qwen3.5, MiniMax M2.5) on a dual GH200 rig (see my other post). Code and new models coming soon.

Happy to answer questions.

hackerchy - 2 minutes ago

This is fascinating. The fact that only ~7 layer blocks work and not fewer/more really suggests there are emergent functional units in the transformer stack that we don't fully understand yet. Almost like "organs" in the network. Have you tried this on architectures other than Qwen, like Llama or Mistral? Curious if the magic block size is architecture-dependent or if 7 layers is some kind of universal constant.

momojo - 11 hours ago

I'm surprised the point/comment ratio is this skewed. There's so much meat in the post to chew on. I like your writing. This was one of those blogs where I can tell you spent a massive amount of time on the technical, but simplified it to layman's terms. I hope you keep putting out stuff :).

I have a couple questions:

1. I think this quote should be raising *many more* eyebrows.

> The astounding thing about Goliath wasn’t that is was a huge leap in performance, it was that the damn thing functioned at all. To this day, I still don’t understand why this didn’t raise more eyebrows.

You put a cat's brain into a dog's head and its still breathing! It didn't flatline immediately! Is yesterday's news? This seems like the biggest take away. Why isn't every <MODEL_PROVIDER> attempting LLM-surgery at this moment? Have you noticed any increasede discourse in this area?

2. You mentioned you spent the beginning of your career looking at brains in biotech. How did you end up in a basement of GPU's, working not in biotech, but still kind of looking at brains?

Again, great post!

imranq - 13 hours ago

Amazing write up and i wish more people showed the process for discovery which is often even more interesting than the result itself

Still the result is really interesting being able to stack abstract reasoning and get better performance and the heat maps to show the prob results

The academic literature seems to be catching up:

- *[SOLAR / DUS (Kim et al., 2023)](https://arxiv.org/abs/2312.15166)* — duplicated transformer layers to build a 10.7B model that outperformed 30B parameter baselines.

- *[The Curse of Depth (2025)](https://arxiv.org/abs/2502.05795)* — explains why this works: Pre-LN causes deep transformer layers to converge toward identity functions, meaning middle layers are where real computation happens, and duplicating them concentrates that capacity.

- *[Scaling up Test-Time Compute with Latent Reasoning: A Recurrent Depth Approach (Geiping et al., NeurIPS 2025)](https://arxiv.org/abs/2502.05171)* — takes the idea to its logical conclusion: a model trained with a single recurrent block repeated at inference time, scaling reasoning depth without adding parameters.

mysteria - 14 hours ago

The astounding thing about Goliath wasn’t that is was a huge leap in performance, it was that the damn thing functioned at all. To this day, I still don’t understand why this didn’t raise more eyebrows.

This wasn't something I really dug into in great detail but I remember my surprise back then at how all those merged models and those "expanded" models like Goliath still generated coherent output. IMO those were more community models made by small creators for entertainment rather than work, and only really of interest to the local LLM groups on Reddit, 4chan, and Discord. People might briefly discuss it on the board and say "that's cool" but papers aren't being written and it's less likely for academics or corpo researchers to notice it.

That being said I wonder if it's possible to combine the layers of completely different models like say a Llama and a Qwen and still get it to work.

Even with math probes, I hit unexpected problems. LLMs fail arithmetic in weird ways. They don’t get the answer wrong so much as get it almost right but forget to write the last digit, as if it got bored mid-number. Or they transpose two digits in the middle. Or they output the correct number with a trailing character that breaks the parser.

Would using grammar parsing help here by forcing the LLM to only output the expected tokens (i.e. numbers)? Or maybe on the scoring side you could look at the actual probabilities per token to see how far the correct digit is.

Balinares - 17 hours ago

The idea that there may be a cognitive lingua franca hiding in the layers is fascinating and gives me hope for a neat idea: pluggable knowledge banks.

MoE notwithstanding, a model trained on the whole Internet and a few hundred thousands stolen books carries way more knowledge than is actually needed for any given workflow. It would be great if we could ship slimmed down models into which we'd plug the knowledge banks useful for today's work, and only those.

It would also mean that you could keep a model's knowledge fresh without retraining the whole of it.

rapatel0 - 18 hours ago

I think you may have cracked latent space reasoning. I've had a hunch that something like this would work, but couldn't figure out how the training would back propagate. But you've shown that you just need to duplicate existing layers.

Have you tried a simple inline loop over the duplicated layers? Would be interesting to see performance. Also, would be interesting to compare with a MOE model. See if these layers are acting like different agreeing "experts" or if there is reasoning happening in the latent space.

iamjackg - 14 hours ago

I find the concept of LLM "brain surgery" fascinating, precisely because of how opaque the network is. One of the first things I did back when llama.cpp first got vision model support was hack the code to zero out (or otherwise modify) random numbers in the image embedding generated by the projector and then ask the LLM to describe the image. It was absolutely fascinating.

It would go from a normal description of the item in the picture to suddenly seeing people clapping in the background that were not there, or making up some other stuff. I kinda stopped after a while, but I should pick that back up and do a more coherent experiment to see if I can find any correlation between vector dimensions and "meaning."

phire - 3 hours ago

That's really interesting. Makes me immediately ask two questions:

1. Should we be training models like this from the start? It seems that a model trained with layer loops would be able to take advantage of it better than rearranging the layers of a naive model.

2. Should we even be using a fixed number of layers? If models are this tolerant to their inner layers being meddled with, then it doesn't make sense to run all the layers on every single token.

Maybe we could make a model that changed the number of iterations through the compute layers based on how much computation it thought the problem needed. Send it through only once for easy problems (perhaps even zero times?) and two or more times for harder problems. This would allow easier prompts to complete faster, while allowing the model to potentially scale up to infinity hard problems.

If we are training or fine tuning the model, we can probably make the compute layers generate a confidence signals based that predicts how likely it is for an extra compute iteration to meaningfully change the result.

Lerc - 15 hours ago

I have had broadly the same intuitions on the use of middle layers, but haven't had much luck with the tiny models that I can run on my hardware.

There's a video on YouTube https://www.youtube.com/watch?v=pDsTcrRVNc0

about a looping layer models, after watching that I poured some thoughts off the top of my head into a comment which, of course, promptly sunk without a trace. I'll repost the gist of them here.

If you gain benefit from looping layers, at some level every layer of parameters is in front of and behind every other, the conclusion must be that the order of the layers does not need to be fixed at all.

If you cycle through the layers multiple times, are you doing so for the benefit of a particular layer on a particular problem. If so, can you skip the other layers that don't add on repetition. If you can skip (and you can know when to skip), and you can repeat (and know when to repeat)

What you would need is a mechanism which can decide which layer is needed next. Is that then not a looping single layer MOE model? Storing the layers as a wide set of selectable options rather than a deep set of unconditional layers. You would be picking what the next layer should be (or exit the loop) the threshold for exit drops each iteration so it always eventually exits. With a tunable 'how hard to think' knob to adjust the threshold.

hmokiguess - 17 hours ago

I really enjoyed reading this. I feel like generalists intuitively experience this exact thing so much throughout their lives because they must have this neuroanatomy you describe. There’s a certain geometry to knowledge that makes possible for this orthogonal movement and it is really fascinating to me. Thank you for publishing this, you made my day!

hex4def6 - 15 hours ago

I've gotta say, this writeup gives me an itchy feeling. It really does feel like poking around a synthetic brain at this point.

You could make the argument it's closer to the blocks of a CPU compared with a brain, and it's no different to copy-pasting some IP block for eg, HW JPEG decoding. But I feel like the difference here is we're 'discovering' these blocks / organs. They weren't designed, they were evolved.

Havoc - 17 hours ago

Crazy writeup.

Author is right about the base64 part. Does seem weird that it can decode and understand it at same time. And I guess what makes it weird that we just sorta accept that for say English and German this works ie normal use but when framed as base64 then it suddenly stops feeling intuitive

supriyo-biswas - 3 hours ago

Thank you for your contribution. Unfortunately I do not have sufficient expertise in LLM engineering to provide a useful comment, but this is the sort of research I'd like to see here instead of LLM-driven unemployment hype.

phn - 15 hours ago

A fascinating thing for me after reading this is: how can it be that the "circuit input" is compatible with its output to the point where the performance improves? The training process never saw this particular connection just like it didn't see layer 60 output into layer 3 or whatever.

Great read, makes you wonder what else is encoded in these models that might be useful!

twotwotwo - 4 hours ago

This is fascinating, and makes me wonder what other things that 'should' be impossible might just be waiting for the right configuration to be tried.

For example, we take for granted the context model of LLMs is necessary, that all you can do is append and anything that changes the beginning requires a recalculation of whatever comes after it. And that does match how training works.

But all sorts of things would become possible if it were possible to shift things in and out of context without recomputing it all; conservatively you could avoid compaction, optimistically it might be a way to get info to the model that's both more deeply integrated than search and more efficient than training larger and larger models.

3abiton - 14 hours ago

Man, that was such an enjoyable read. I loved your story on the wild server hunt, back when it was posted on r/localllama. I think one thing that is missing from the whole AI "discussion" is this train of thought of how we go from abstract mathetmatical formulation to intuitive understanding of the underlying functionality, and you showcased it beautifully in this article. Similarly to 3blue1brown who also did an amazing series on transformers. Kudos!

tgw43279w - 19 hours ago

That was a fun read! The base64 decoding and encoding is quite interesting. A parallel: these models are surprisingly robust to heavy word mangling, back in 2023 people used this trick to jailbreak the models very often, but what was more surprising is that they even understand it. I always thought of it this way there must be some circuitry in the model that maps these almost unrecognizable words/sentences into their rectified versions. But what your base64 also shows is the fact thy can also encode them back as well! (However models are known to not be able to produce mangled output that looks convincingly random. I think the base64 transformation is more mechanical in this regard and hence it‘s easier to do the reverse for them.) So your layer circuit hypothesis aligns pretty well with my mental model of how these models work based on the interpretability work I am familiar with! I really also like the way you used the heatmaps as a tool to derive layer insights, very intuitive! But it’s really surprising that you can simply duplicate layers and achieve better results that generalize! This is some research grade effort! I’m confident you could publish this in NeurIPS or ICML if you put it into a paper! I‘m quite impressed! Great work!

digdugdirk - 18 hours ago

Super cool! Do you do any analysis or have any tools that help you identify these circuits? I came across this [1] recently, and wanted to try to identify specifically strong "circuits" in what seems to be a similar way to what you did.

[1] https://weightwatcher.ai/

WithinReason - 18 hours ago

Here is a paper that made a similar observation recently:

https://www.alphaxiv.org/abs/2512.19941

cootsnuck - 18 hours ago

Super cool. Love seeing these writeups of hobbyists getting their hands dirty, breaking things, and then coming out on the other side of it with something interesting.

dubbel - 9 hours ago

Absolutely amazing blog post!

I have to say that intuitively I wasn't at all surprised that duplicating a single layer didn't do much good, but I had never expected that you can identify and so clearly visualize these relatively short circuit blocks (and of course it's around the magic number 7! /jk). Super cool research and really well explained!

user_7832 - 17 hours ago

Thanks for the post, really cool stuff you did!

Extra thanks for making it written in a readable and approachable way! I don't have much of a background in this topic, but still managed to understand about 70-80% of it :) You're a good writer

siliconc0w - 7 hours ago

Great insight and approach. I wonder though if instead of blogging this, he have the top labs bid on it - what that'd fetch?

janalsncm - 13 hours ago

It would be extremely interesting if we could use this kind of model surgery approach to tack on additional modalities. For example, adding vision to a text only model.

Another very interesting thing would be modulating compute at the token level. Default is 0 loops, maybe 1 loop is better, and 10 loops is even better than that.

dgoet - 9 hours ago

Fantastic. Really gets me thinking.

If more than two repetitions of the “thinking organ” leads to worse results (I think that’s what you’ve said in other comments), would it be possible to get better results by slicing and dicing some of the early-layer “preparatory organs” between the thinking organs?

Maybe that would still require fine tuning to “evolve” an intermediary organ that would allow for multiple repetitions.

dnhkng - 16 hours ago

Here's an extract, the core TL;DR for a feel of the article.

"And now for the weirdness: There was never the case where any Transformer layer would have seen the output from a future layer!

Layer 10 is trained on layer 9’s output distribution. Layer 60 is trained on layer 59’s. If you rearrange them — feeding layer 60’s output into layer 10 — you’ve created a distribution the model literally never saw during training.

The astounding thing about Goliath wasn’t that is was a huge leap in performance, it was that the damn thing functioned at all. To this day, I still don’t understand why this didn’t raise more eyebrows.

Experimentally, this proved that layers were far more interchangeable than anyone had reason to expect. The internal representations were homogenous enough that the model could digest out-of-order hidden states without collapsing. The architecture was far more flexible than a rigid pipeline.

Between the Base64 observation and Goliath, I had a hypothesis: Transformers have a genuine functional anatomy. Early layers translate input into abstract representations. Late layers translate back out. And the middle layers, the reasoning cortex, operate in a universal internal language that’s robust to architectural rearrangement. The fact that the layer block size for Goliath 120B was 16-layer block made me suspect the input and output ‘processing units’ sized were smaller that 16 layers. I guessed that Alpindale had tried smaller overlaps, and they just didn’t work.

If that was true, maybe I didn’t need to teach a model new facts to make it smarter. I didn’t need fine-tuning. I didn’t need RLHF. I just needed to give it a more layers to think with."

goodmythical - 17 hours ago

Isn't this similar to models that have "double check the answer"?

First pass runs your input through, second pass runs it's output as input?

Just, in double check it presumably runs the entire stack while you're trying to skip the translation steps and only double check the logic?

kovek - 17 hours ago

Is this similar to send 48656c6c6f2c20686f772061726520796f753f in the prompt? As done here: https://youtu.be/GiaNp0u_swU?si=m7-LZ7EYxJCw0k1-

blourvim - 20 hours ago

I am not really an ml dev so I don't understand most of it. It does sound ridiculous how it would even work work. Brilliant work and great article I enjoyed reading it

This sounds similar to the Kimi's mixture of experts architecture if I understood it correctly(likely I have not), can you comment on this ?

dongecko - 16 hours ago

What a great read! You got me at the base64 oddity. I also stumbled over this, while trying to dodge some LLM limitation. (was trying to generate images in a time before multimodal was a thing. it only worked to a degree).

tjwei - 18 hours ago

Really interesting discovery, especially the part about base64. Reminds me of this: Transformer Layers as Painters https://arxiv.org/abs/2407.09298

Aditya_Garg - 17 hours ago

Wild stuff and great read

Do you think karpathy's autoresearch would be useful here?

Xuzzo - 11 hours ago

Fascinating! Congrats for the great work

BloodAndCode - 14 hours ago

Did you try repeating the same mid-layer block more than once?

If the gain comes from giving the model another pass over its internal representation, I'd expect some sort of diminishing-returns curve as you add more repeats. But if those layers form a spevific circuit, running it multiple times might actually break the computation.

It would be really interesting to see which of those regims the model falls into.

lifis - 11 hours ago

Have you tried replicating those middle layers 3 or more times instead of just 2?

d0100 - 15 hours ago

I wonder if joining layers from the "organs" of different models could further enhance the results

jauntywundrkind - 18 hours ago

The dual GH200 build was amazing. Awesome to see someone with such talent & flare in one area also doing great in another area. Thanks for noting that that was you. https://news.ycombinator.com/item?id=46222237

kristianp - 13 hours ago

Does your work give any insight into how reasoning at inference time works?

lordmathis - 17 hours ago

That's cool. I tried the b64 thing on my local qwen3.5 27b without access to tools and it did it.

Handsome2734 - 6 hours ago

Fascinating write up!

opendeck - 2 hours ago

This is fun!

GaggiX - 17 hours ago

This reminds me when people were doing crazy stuff to improve the first Stable Diffusion model by swapping layers, interpolating weights, documenting which layer was most responsible for the quality of the hands etc. At the end the final models had dozens of different ancestors.

patchnull - 17 hours ago

This lines up with what I have seen doing CKA (centered kernel alignment) analysis on transformer internals. The middle layers in most large models have surprisingly similar representations to their neighbors, so duplicating them is basically giving the model extra compute cycles in a region where it is already doing useful refinement without messing up the input/output encoding stages. Curious whether picking layers by representation similarity instead of just a contiguous block would do even better.

vicentwu - 6 hours ago

Good read.

afpx - 17 hours ago

Thank you so much for sharing this in a delightful blog post. One of the more enjoyable things I've read in a while. Very motivating!

FergusArgyll - 8 hours ago

Someone get this guy more 4090s!

seeknotfind - 18 hours ago

Did you ever try multiple copies?

naasking - 18 hours ago

This layer duplication strikes me as a bit of "poor man's" version of looped language models:

https://ouro-llm.github.io/

Pretty cool though. LLM brain surgery.

- 20 hours ago
[deleted]
rob_c - 17 hours ago

very awesome writeup, glad to see someone with access to hw actually playing with this.

Hopefully the cost per GPU will kick-it soon and we'll see people properly play, but frankly the "middle section" layers 2(ish) to (n-1)(ish) of a model can be shuffled up/down and left/right and still perform well.

The fun one will be an LLM router for LLM layers to apply the best reasoning to the best input so far, but frankly that would need the years and years of training that the author hints at.

The one that's still out of grasps is still how to combine/manipulate per-layer k,v caches into a globally coherent state. i.e. if layers can be moved up/down why can't the cached k,v be swapped/combined with different projections? global k,v caches work, but they have to be _huge_ in order to prevent model collapse even on something as simple as owt.

priowise - 17 hours ago

[flagged]

phacker007 - 9 hours ago

I'm so dumb

himmi-01 - 12 hours ago

How did you get this idea? What was the inspiration behind it? I mean who would of duplication :) ?!