Nvidia Nemotron 3.5 Lightning and NeMo Switchyard (blogs.nvidia.com)
233 points by droidjj 15 hours ago
kentonv 10 hours ago
Coincidentally I've been playing with small (~30B) self-hostable models for coding tasks today -- specifically plugging them into Cloudflare OS (which I work on) and asking each to build a collaborative whiteboard.
I'm finding that the Mixture-of-Experts (MoE) models (Qwen 3.6-35B, and Nemotron 3.5 Lightning) are, well, terrible at this. They just couldn't get the job done at all. Went way off the rails. They are really fast though!
Whereas ~30B dense models (not MoE) are pretty decent. I tried Muse Glimmer, Gemma 4-31B, Qwen 3.6-27B, and Laguna XS[0]. They were all able to build a working collaborative whiteboard app, without any guidance (other than feeding back error logs to the model). I also asked each to then draw a monkey by calling the API of the whiteboard it has just built. Laguna drew random scribbles but the rest all managed to produce something monkey-like.
(Frontier models in comparison will write the app in one shot with no errors at all.)
Note that both Qwen 3.6 and Gemma 4 each have both MoE and dense variants. I find this very confusing, because e.g. ollama's model index typically only distinguishes variants by their size, but MoE vs. dense makes a huge difference in how they actually perform. IMO they should use a suffix, like Qwen 3.6-moe vs. Qwen 3.6-dense, or maybe Qwen 3.6-fast vs. Qwen 3.6-smart...
[0] EDIT: Turns out Laguna XS is MoE, I misunderstood. It performed similarly to the dense models. But maybe this explains why it couldn't write code and think about monkey shapes at the same time!
zargon 7 hours ago
> ollama's model index typically only distinguishes variants by their size
Don't use ollama. The entire project is just a series of stupid decisions like this.
kristjansson 6 hours ago
How they have any credibility after they told everyone they could run Deepseek R1 on their laptop (by giving the Qwen 7B distill the `deepseek` moniker)...
Foobar8568 3 hours ago
And last time I have checked, you still can't run rerankers with it, yet you can download the models. See issue 3368, 2years old now.
natrys an hour ago
There is an old rule of thumb that says the quality of an MoE is equivalent to a dense model with the geometric mean of its total and active parameters. So, for example, the Qwen3.6 would be equivalent to a dense model with approximately sqrt(35×3) ≈ 10.25B parameters.
Both MoEs and dense models are always getting better, so I don't think this comparison is meaningful across generations. But still for a first approximation, this tends to hold (you wouldn't expect a lot from a 10B model in coding yet).
ChadNauseam 10 hours ago
I've been pretty impressed with Laguna. I downloaded their coding agent and have used it for a task here and there (the larger variant). Obviously it's nothing like a frontier LLM, but it surprised me with how good it was. And I think the model personality and way it talks is pretty pleasant
dd8601fn 8 hours ago
I’m confused about the naming suggestion. Seems like the AxB bit differentiates pretty clearly, no?
kentonv 6 hours ago
Only if you know what it means. To many people these suffixes are gibberish. Also ollama doesn't actually show that suffix in its model index. Don't say "don't use ollama", you sound like a Linux user telling people not to use Mac. (I say this as a Linux user who despises Apple products myself.)
literalAardvark 5 hours ago
Ollama uses "consumer UI guidelines", it's the second worst AI tool to use for anything more than writing fanfic.
msdz 3 hours ago
Now I have to ask – which is the worst?
woadwarrior01 an hour ago
Good luck writing fanfics with primitive top-p and top-k samplers.
sroussey 8 hours ago
What’s good for data extraction? I have a hard time getting models to just pull names and titles from a blob of text.
rufasterisco 6 hours ago
Build/vibe-code your own benchmark and find out, the work pays off and lets you try many models.
Also try fine-tuning small models and see how they perform.
usagisushi 6 hours ago
If you haven't yet, you might want to try gemma-4-E4B-it-qat or gemma-4-12B-it-qat with Structured Outputs. My main use case is tagging photos and generating headlines.
trouve_search 10 hours ago
Laguna XS is MoE, however.
kentonv 10 hours ago
Oh!
I think I missed that and assumed it wasn't because it performed similarly to the dense models. Interesting!
SwellJoe 7 hours ago
jmward01 14 hours ago
One major consequence of the ramapocalypse, I think, is an even higher focus on small efficient models. I personally believe that the multi-trillion parameter models are fundamentally missing things and the push to smaller, more efficient will drive evolutionary structural changes that will lead to future gains
cogman10 13 hours ago
I'd assume the closed weight models are all working on shrinking their parameter counts anyways. They too benefit from smaller models. It'd be foolish for these SOTA labs to not be working at reducing parameter counts.
literalAardvark 5 hours ago
The incentive is there, but their money making niche is to solve problems you can't solve locally with a 30b, so they're unlikely to stray into territory owned by ultra cheap to run open weights models.
cootsnuck 13 hours ago
I would say even without rampocalypse there would still be the strong incentive to innovate at the edge and under more extreme constraints. The incentives are just even stronger now.
I'm looking forward to seeing what types of new things people create over the coming years once there is less obsession with massive unwieldy LLMs. I think the incentives are just too strong to ignore.
XCSme 12 hours ago
This is just temporary though, right?
With the benefit of LLMs already being proven, in a couple of years we will have vastly better hardware for inference I guess.
I feel like now hardware is stagnating a bit, because the software side has moved too fast for the hardware to catch up. Once we settle on some good, optimal software architecture for the models, dedicated hardware will easily increase throughout by 10x or 100x, for a fraction of the cost.
LLMs seems quite simple, maybe we'll be able to print/assemble at home our own chips with the desired models/weights.
Maybe we'll have model weights being shared like game cartridges.
dragonwriter 12 hours ago
> This is just temporary though, right?
Well, everything—even human life on Earth—is just temporary, but RAM supply lagging centralized-AI-driven demand increases continuing to squeeze the consumer market may not be a short term phenomenon.
> LLMs seems quite simple, maybe we'll be able to print/assemble at home our own chips with the desired models/weights.
So, the solution to the RAM crunch is “everyone has their own home chip fab and deals with the raw material supply and hazardous waste disposal”?
I...don't imagine so.
XCSme 11 hours ago
jmward01 12 hours ago
I personally think of this like sorting algorithms. Quick sort does the same thing bubble sort does so why do we need quick sort? Pushing for efficiency drives innovation. It does this for many reasons but a big one is that putting a cap on a resource forces you to consider the others available and often you find that all it took was a little effort and suddenly the alternate path that looked a little worse is actually better than you realized.
This has a lot to do with how MCTS works BTW. The current best path is often only the current best path because a lot of investment has been sunk into it. If you were to put equal resources into a different path you may find that it was actually far better. It is just that the early rollouts favored the other 'best path' so you sunk a lot of resources into that one. We are very early in our exploration of LLM architecture. I highly doubt we are anywhere near the best path right now.
XCSme 12 hours ago
sixothree 12 hours ago
I fear the future of local models will be controlled by governments. I feel like some time soon there's going to be a crackdown on what is available to download, what is hostable, and what is "acceptable". I partially suspect it has something to do with why 128 GB seems to be the most you can currently purchase for a single machine, despite the price.
matheusmoreira 12 hours ago
schainks 14 hours ago
I am literally betting my company on this being true.
itsmeduncan 13 hours ago
Me too. I think there are a few waves we can ride here. Let's collaborate?
jmward01 13 hours ago
What company? I am 100% focused on this as a concept in my own internal research.
oblio 13 hours ago
It's a bad bet, historically.
I'm having an extremely hard time thinking of companies that have prospered due to software optimization. Most of them were swept away by hardware advances, instead.
jmward01 13 hours ago
somethingweird 13 hours ago
hgoel 13 hours ago
cootsnuck 13 hours ago
polymer8563 13 hours ago
b3ing 7 hours ago
I hope ssd streaming gets more popular, maybe more breakthroughs like that will help change things
whimsicalism 12 hours ago
I think the path of least resistance will end up being the cheapest and that is scaling up the parameters a ridiculous amount until you get highly capable models that can develop/distill/design the RAM efficient models. Going straight for low param is foolish and just a cope by smaller labs because they don't have the compute/talent to train the large ones.
This is 100% true for pretrains, likely true for RL as well although maybe there is some benefit to smaller activated params there. There is of course 0 benefit to small dense models relative to large sparse ones that are equally as memory efficient if you have enough computers.
Many on HN are in deep denial about this imo.
ashu1461 10 hours ago
Right now there is a stark difference between what smaller models can do and bigger models can do.
Smaller models are suitable for simple tasks like classification / summarisation while larger models are better in agentic capabilities.
astrobiased 10 hours ago
Depends on the type of agentic task though. For simple operations, a small model can be quite beneficial.
jrflo 12 hours ago
Let's not forget the Bitter Lesson. Small models sound really nice but at some point you're just fighting the laws of information theory. Efficiency gains on the small model side are nice, but efficiency gains + giant model tends to be even better...
kgeist 9 hours ago
More compute/larger datasets during training != larger models. The Bitter Lesson was that just scaling things up beats custom hand-crafted optimizations. Up until 2024, we thought that meant scaling up the parameter count, but then that started to plateau. After o1 was released, we thought it was about scaling up test-time compute. Now, seeing how 30b models can easily outperform 200b models from a few years ago, it seems like what we need to scale is RL, at least for agentic capabilities. It looks like 30b is already enough for good agentic capabilities. Larger models aren't considerably "smarter" (especially since they're mostly MoE anyway, with something like the same 30-50b active parameter range), they just know more (better world knowledge), which lets them make more informed decisions. Maybe we just need to scale up the retrieval layer.
jrflo 9 hours ago
anon373839 11 hours ago
I feel like the industry has quietly moved past the Bitter Lesson. In 2023 the story was naive parameter/data scaling and “emergent” intelligence properties. But there wasn’t enough data or compute to keep pushing in that direction, and the gains from it have been sublinear anyway.
Now, the labs spend enormous effort curating data pipelines to fit the models to a large assortment of very specific tools, tasks, harnesses, domains, etc. They also kind of fit to benchmarks by creating loads of synthetic training data that resembles benchmark tasks. None of this feels like the “scale up primitive methods and turn off your brain” message Sutton originally delivered.
boredatoms 11 hours ago
How many bits of information are in a real brain?
wslh 8 hours ago
jrflo 9 hours ago
NBJack 14 hours ago
I honestly hope to see this across all applications, games, services, operating systems, etc. We've been in a period of wasteful RAM usage for over a decade. Constraints, whatever their origin, can be a good thing.
pjmlp 13 hours ago
Same here, back to when algorithms and data structures mattered.
oblio 13 hours ago
If China makes half decent RAM I would bet more on things like 128GM of RAM being the default on low spec laptops 10 years from now.
While I do love optimized software, the hardware side, especially for PCs, has been stagnating for way too long. At least now we have a valid use case for doubling available RAM every 2-3 years again.
I had a reasonably beefy Lenovo consumer line laptop that I bought in 2011, 8GBs of RAM. Its screen hinge broke and I couldn't repair it but I'm fairly sure it was otherwise still usable in 2023-24, once the HDD was replaced with an SSD. I think even now entry level laptops are sold with 8GB of RAM.
By comparison a PC from 2000 was utterly unusable in 2012-13.
KaiMagnus 13 hours ago
mortsnort 12 hours ago
Really? I feel like because nobody has RAM they're being pushed to the cloud frontier models. If we could all have our own 64GB+ VRAM GPUs, I feel like the open weight model scene would be even stronger.
thehamkercat 15 hours ago
> NeMo Switchyard, an open source library for smart routing
> When deployed, NeMo Switchyard can intelligently direct each request to the most capable and suitable model for the job
How do routers like this handle prompt caching when you send the second request?
Sticky models per session? but then the second message of that session won't be sent to a suitable model, and will only be sent to the same model as previous one.
eli 15 hours ago
I've seen ones that are configurable to pick a trade off point between lower cost (cache stickiness) and routing performance (best model for that turn).
But yeah I'm skeptical all this overhead is worth it.
rufasterisco 6 hours ago
https://github.com/NVIDIA-NeMo/Switchyard#routing-strategies
Looks like your great question doesn’t have an answer, but looking at the routing strategies things get even more confused, since the proposed ones tend to rely on extra llm calls to determine which model to pick.
The nice thing is that it makes sense for specific setups, less conversation oriented.
As an example, you need to classify batches of data, and have many fine tuned models. Or you need to do speed to text and need to pick which whisper to use.
You can write your own strategy, in that case an harness with subagents would be able to leverage this, picking the right model and then keeping its session sticky, but overall the lack of concern for caching points towards use cases where you do not gain much from it.
embedding-shape 15 hours ago
The repo is probably a better entrypoint to it, bit more concise description than the press releases: https://github.com/NVIDIA-NeMo/Switchyard (Notably: "Experimental software. Not for production use."). Unclear if they actually want you to deploy it or not, press release says yes, README says no, do with that what you will.
Doesn't seem to mention "cache" in the README nor the docs, but the code has mentions of it (https://github.com/search?q=repo%3ANVIDIA-NeMo%2FSwitchyard+...), I'm not sure what their thinking is there. "Good luck" essentially? Seems to be per-provider at best, but weird position for a routing library to take.
thehamkercat 15 hours ago
I personally think it's snake-oil marketing with all these smart-model-routing products/projects
prompt-cache won't work with these
try-working 15 hours ago
quinncom 13 hours ago
Caching should be possible as long as all the models use the same shared cache. The models don't even need to be running on the same server if the shared cache is distributed.
I have a feeling people reading this are thinking that a model router would be used to route between different providers. And in that case, a shared cache would be impossible, although some caching would still be effective. I think, ideally, a router like this is in front of a set of models hosted in one place.
IanCal 13 hours ago
How do caches work across models? I would have thought that was very model specific - if not I’ve really misunderstood what’s getting cached.
armanckeser 13 hours ago
amluto 13 hours ago
Huh?
Prompt caching isn’t about caching the literal text of the prompt. It’s about caching the result of running prefill on the prompt (or, equivalently, the result of generating the prompt one token at a time by autoregressive inference, or some combination of the above in the case of speculative decoding). This is often called the “KV” cache, and it is very model-specific.
docheinestages 13 hours ago
They conveniently decided not to include the Qwen range of models in the Artificial Analysis graph, except the out-of-league Max variant. At least be brave and honest.
average_bloke 14 hours ago
I would like to propose something:
- problem: massive deluge of information because of AI
- solution: human beings should adopt a minimalist style of communicating in writing.
- e.g. this entire website page can be ten bullet points.
AlexB138 7 hours ago
There's a famous Pascal quote, "I have only made this letter longer because I have not had the time to make it shorter."
Communicating an idea concisely is difficult. Most people struggle to get ideas across at all, asking them to do it well with fewer words is often out of reach.
ygouzerh 6 hours ago
This resonates well with engineers: making something complex is easy, making them simpler is harder
throwatdem12311 12 hours ago
Why use more words when few do trick?
dofm 11 hours ago
nods
fooker 13 hours ago
k
stavros 13 hours ago
While I agree with the spirit, I don't think the solution to bad prose is slightly less bad prose. We can write good prose instead.
encrux 14 hours ago
In my opinion: the only way forward is zero-knowledge-proof authenticated social media.
We can’t have legitimate debate if we have to assume a few bad actors are cloning their voice by the thousands, poisoning debate.
If we can pin one account to a real person, we won’t get rid of LLM-content and misinformation, but at least we can hold them accountable.
ttoinou 14 hours ago
Is the network based on trust and peer to peer confirmation of private keys from who you know in real life that you validated isn’t a robot ?
Or do you have something else in mind ?
kubelsmieci 14 hours ago
> We can’t have legitimate debate
I'm not sure people really want that
ashu1461 10 hours ago
it takes more effort to write with conciseness
jamiek88 11 hours ago
Judging by how my nieces and nephews text this has already happened!
sp1nningaway 11 hours ago
hell yeah
WalterGR 15 hours ago
24 comments so far about Nemotron on this earlier submission: https://news.ycombinator.com/item?id=49257947
mark_l_watson 12 hours ago
I love the wave of new small model releases. Pleasantly surprising that an NVIDIA model runs so well on Apple Silicon using MLX! I was using nemotron-3.5-lightning:30b-mlx with OpenCode on my old (cheap) Mac this morning and no bad experiences except for running slowly.
macwhisperer 6 hours ago
big week for open models... seems like companies are noticing the 26-35b sweet spot... though I think a 12b-a1b-MoE model would be helpful for the 16gb folks
jadbox 13 hours ago
Nemotron 3.5 Lightning runs on how little GPU vram? Can q4 run on 16gb?
sleepyeldrazi 13 hours ago
Not by the looks of it, but it got me thinking, currently in the middle of Level1Techs coverage on the model and switchyard and he mentions "how easy it is to customize it". Fully admitting that I haven't yet read the docs, my issue with that is "we can train LORAs for 35B as well, why use this (according to benchmarks) worse model for customization instead of a slightly bigger better one?"
Assuming I eat my words after going through the docs and this is actually a more efficient model / loras adapt better, I don't see as much value in it as is, as a REAP of it (remove least-important experts, domain-locked tests show ~98% retained accuracy) to something like 20B-A3B (rouhgly matching gpt oss, which while a good model, is outdated knowledge-wise and not as good with tool in my xp).
Having a 20B-A3B model at q4 that has a lora to be your local orchestrator (delegating coding to server/cloud models) and ci/cd runner does start sounding like an appealing proposition to me, as that would fit in 16gb vram easily (fitting many consumer gpus and 24gb macs).
HackerThemAll 3 hours ago
An open source model from Nvidia is a free drug to later buy their chips.
halfdeadcat 10 hours ago
Good luck getting it to run with NVFP4 on a DGX Spark, the very architecture Nvidia created that format for.
XCSme 15 hours ago
The new Meta 30B models seems A LOT better:
https://aibenchy.com/compare/meta-muse-glimmer-30b-xhigh/nvi...
thehamkercat 14 hours ago
Muse Glimmer 30B seems to be on par with Qwen 3.6 27B (4 months old)
but
Qwen 3.8 27B is dropping this week...
XCSme 14 hours ago
Yes, I was surprised to see doing it as well as Qwen 3.7 27b.
Even though that model is already "old", qwen was way ahead everyone else in that size category before this Meta model.
Also, probably for non-Chinese usage, using a non-Chinese model might lead to better results.
eli 15 hours ago
The top 4 models on that site are all variants of Gemini Flash? That does not match my experience at all.
XCSme 14 hours ago
I should add a F.a.q. for this question.
The suite is across many categories, not only coding, and most of the tasks are low-horizon (or what the opposite of long-horizon is), where the max thinking time is around 10 minutes.
Gemini models are really smart, unfortunately they don't play well with any harness, so hard to use in practice.
But try them out for one-shot tasks, they are really good. Don't use them for coding in a harness, but you can ask them to generate code/planning (still, for coding only other models are indeed recommended).
markasoftware 13 hours ago
yep, the person you're responding to created the benchmark and is using HN comments as advertisement.
XCSme 12 hours ago
Tactical45 15 hours ago
At what cost difference?
XCSme 14 hours ago
I don't think it matters, if it's for local/on-device usage.
The cost is similar vram footprint I guess (?)
sleepyeldrazi 12 hours ago
khimaros 13 hours ago
lightning is sparse, glimmer is dense
XCSme 12 hours ago
Oh, good to know, I just quickly tested and published the results.
I will add model sizes (total/active params) for each model, good point.
rllearneratwork 13 hours ago
and Glimmer has 10x active params of Lightning. Meaning ~ 10 slower on same HW
XCSme 12 hours ago
Is that the case?
If the entire model fits in vram, won't the tps be comparable?