Running Kimi K3 on MI355X at Better Performance per Dollar Than B300
Posted by ilreb 1 day ago
Comments
Comment by venkat_2811 3 hours ago
Comment by GuestFAUniverse 1 day ago
Even without the base system, power and every other expenses: 365d * 24h * $2.95 = $25842/a invoicable.
That doesn't add up within one year, that doesn't add up in three years and it is questionable that it brings in the money during the lifetime of the device?
Comment by gpugreg 1 day ago
Comment by swiftcoder 1 day ago
Is anyone actually renting them out that cheap? The very cheapest on-demand price I see online is $14, and most providers are a lot higher
Comment by arjie 1 day ago
Comment by inferencecoder 1 day ago
> $2.50/GPU-hr for the MI355X, $6.00 for the B300, and $4.25 for the B200.
This is not an accurate price comparison for real terms.
Comment by greyb 1 day ago
Comment by villgax 1 day ago
Comment by YetAnotherNick 1 day ago
Comment by BoorishBears 11 hours ago
Not to mention no one serious is serving this on 8xB200 instead of multiple nodes: the vast majority of Moonshot's inference work is focused on PD-disaggregation
Comment by inferencecoder 10 hours ago
The GPU price discourse is absurd, but many are serving models on single node setups when the model fits
Comment by logicallee 1 day ago
>The fix was trivially simple: zero-pad the head count 12→16, run the fast kernel, and extract the real 12 heads from the output.
I've recently used a frontier AI (ChatGPT 5.6 Sol on ultra) to set up a much smaller local model, and the performance optimizations it introduced left the model totally incoherent. (The model just repeats a single character, etc.)
When I see a line like the one I just quoted, it leaves me wondering if the setup is still coherent like a stock install of Kimi K3 on supported hardware.
Did they run any benchmarks on it to see if it is still correct?
Comment by springtimesun 1 day ago
K3 does an ok job of setting up, but its config searching isn’t nearly as thorough and its will confidently tell you it’s found the best setup when it’s only turned a few knobs. It’s also not a good evaluator of its own output. It rates its work too highly and seems kind of defensive when benchmarking. Still a good check because it does find stuff, but open a fresh session and don’t tell it where the results came from.
What K3 does do more than any other model I’ve found is investigate folder structures. If I want to benchmark it and other models I have to move the testing methodology and any reference to other results out of the project folder bc Kimi is like an ls bloodhound. It will find them.
Comment by serf 20 hours ago
on one hand , yeah : a model being more aggressive towards exploration of the decision space is usually a good thing.
on the other hand : I think that it's up to the operator to set rigid test criteria to make these things actually work well in a repeatable fashion.
so in other words, i'm glad claude is doing a better job for the way you're prompting the thing, but as a spectator from afar these kind of operator complaints usually spring up from the use of weak, ambiguous, under-considered prompts.
similar with the parents' complaint; there should have been a testing criteria for legible output that got immediately flagged or failed by the larger model.
it's a very hard sell for me to think that " a a a a a a a " is accepted as a valid language output by any near-SOTA-large model without some real coercion.
Comment by springtimesun 16 hours ago
It seems like you read my comment as dissing Kimi. Kimi is in regular rotation for me. Some tasks that Claude used to own go to Kimi first now. They are just different tools with their own strengths and weaknesses.
Comment by logicallee 14 hours ago
Comment by technoabsurdist 21 hours ago
and then u must pass test regarding thinking, coherency, and tool calling
Comment by pertymcpert 10 hours ago
Comment by hereme888 21 hours ago
It's basically a Wafer/AMD advertisement.
B300 is about 46% faster for one stream and 65% faster in aggregate. AMD wins only after Wafer divides throughput // selected cloud-rental prices: $2.50/GPU-hour for MI355X versus $6 for B300.
Benchmarks are unreproducible, power costs are missing, ROCm was patched... and on and on.
Sure, it can serve that particular model at that particular size more economically. Good for them... in particular.
Comment by fancyfredbot 20 hours ago
Comment by kelnos 1 day ago
They published the weights. It's an "open weight model", a term that it seems nearly everyone has agreed is appropriate. Why is this company not using it?
Comment by HarHarVeryFunny 1 day ago
That's not totally true - for example Ziphu (Z.ai, developers of GLM) have published their Slime RL-training framework, developed together with Tsinghua University.
https://github.com/THUDM/slime
Also, if you read Moonshot's Kimi 3 report, it does give a lot of architectural detail and details on training.
https://github.com/MoonshotAI/Kimi-K3/blob/main/k3_tech_repo...
Some discussion on this by HuggingFace here:
https://www.youtube.com/watch?v=MW8-kqd2SD8
Yes, we all realize that "open weights" is more accurate than "open source", and anyways the source code would not be very interesting - it's the training data and methods that mostly define these models.
Comment by Almondsetat 1 day ago
I can understand not wanting to call it open source if they don't give you the algorithm and software used for training, but wanting the training data too? That's completely different
Comment by croes 1 day ago
You can‘t reproduce the LLM without the same data
Comment by anon373839 1 day ago
People keep trying to shoehorn OSS concepts onto model weights, but the concepts don’t fit because the weights aren’t software. They aren’t compiled code. They are learned parameters to use with a (very big) function that itself is expressed in the code.
So they’re a very valuable asset that complements the code, but they are not the code. You could use randomly initialized weights and the software will work - it will output tokens. They just won’t have useful patterns.
I don’t think OSS definitions have ever required that assets have their source included. For example, artwork is very important to a game, but nobody thinks a game is not open source if it doesn’t come with sketches and a copy of Adobe Illustrator to recreate the artwork from scratch.
Edit: The distinction I would draw between models like Deepseek and models like OLMo is whether they are open science. With a model like OLMo, they have published everything you need to replicate the training experiment. Whereas Deepseek does share a lot of knowledge, but keeps a lot proprietary too.
Comment by pocketarc 1 day ago
Comment by gpm 1 day ago
Source as a word has a meaning that doesn't include non-source things.
Comment by SV_BubbleTime 23 hours ago
And we have Open Weights to define what those are.
Comment by gpm 23 hours ago
BAR is an open source game. All the game source is open.
Comment by SV_BubbleTime 23 hours ago
Comment by gpm 22 hours ago
> Open source RTS game built on top of the Recoil RTS Engine
BAR is a game, Recoil (a different thing - not the repository I linked) is an engine it is built on top of. Recoil is - incidentally - a fork of spring, an engine many open source RTSes are built on.
Comment by BoxOfRain 1 day ago
Comment by anon373839 1 day ago
Comment by gpm 1 day ago
Comment by ungovernableCat 23 hours ago
I'm not sure how static training data is either (or how you'd distribute it considering its size and nevermind the legality of sharing copyrighted things).
You'd likely get a model with very similar behaviour but the weights would be different.
Please someone correct me if I'm wrong.
Comment by fooker 23 hours ago
Model training now is not a straight forwards process of input data -> run tools -> get model.
There's a whole lot of alchemy going on. We don't quite understand what works and what doesn't. Think of it like painting with water color and having to improvise very often.
The only advantage over water color is that we can revert to a working state.
Comment by SV_BubbleTime 23 hours ago
Really, it’s no more open source than a free calculator. It’s free, and you can use it to no or great effect. But, you sure as hell can’t make one.
So calling it open source is without question, wrong.
Comment by fooker 23 hours ago
It's mostly ad hoc scripts and some pretty horrible hacks being run by a hundred engineers trying to improve a thousand different things at once with a hundred thousand GPUs.
I'm sure once we understand the tech better, the training process will look like running a program.
Comment by WithinReason 1 day ago
Comment by girvo 1 day ago
Comment by croemer 1 day ago
Comment by HarHarVeryFunny 35 minutes ago
These models are a combination of a small amount of code, a ton of training data, and a ton of expertise in how to train them (which I suspect includes how best design/curate training sets for different model improvement goals).
The Chinese models are mostly very well documented in terms of architecture and training processes/flows, with what is missing to recreate them being the training data.
You don't need the source code - just read their architecture docs and implement it yourself.
The Chinese have actually been very open about training, starting perhaps with the DeepSeek-R1 paper which told the world in detail how to train a reasoning model. The Kimi 3 paper also gives a lot of training details.
There really isn't much of a comparison to be had between building a traditional software project where all you need is the (maybe open source) source code and the Makefile that automates the build process, and building a machine learning system where it's primarily about data not source code, and even with a road map of what may be very complex training (cf build) process, you'd probably still have a hard time building it since AFAIK the training process may still involve expert knowledge and intervention - I don't think training has been reduced to a hands-off "Makefile" or build script.
So, basically lack of source code is the least of the issues in being able to build one of these models - it's mostly the training data and training processes/expertise that you would need.
Comment by swiftcoder 1 day ago
Comment by croemer 1 day ago
Open source has benefits even if you can run yourself. You can read the code for understanding/insights. Other labs could replicate/build on it.
Comment by gpugreg 1 day ago
I sure wish I had a few 100M of disposable income to train a frontier model.
> or in the future it could be useful when training is cheaper.
I do not think that physics will allow hardware getting that much faster. But maybe we will have different, cheaper architectures by then.
Comment by halJordan 1 day ago
Cant stand when you guys try and force something as impossible on the rest of us simply because you could never accomplish it.
Comment by gpugreg 1 day ago
(Also, I know Tom Jobbins (TheBloke), and have personally contributed to increase the adoption of GGUF, e.g. in the transformers and ktransformers libraries, so I find the personal dig quite amusing.)
Comment by Muromec 1 day ago
Comment by gpugreg 1 day ago
Unfortunately, electricity prices did not fall by the same factor, so I fear that training a frontier model will still cause a an unsustainable dent in my monthly budget.
Comment by croemer 1 day ago
https://chatgpt.com/share/6a6f3f3b-7624-83ed-a11a-248cb39728...
Comment by eptcyka 1 day ago
Comment by solarkraft 1 day ago
Comment by croes 1 day ago
Comment by WithinReason 1 day ago
Comment by HPsquared 1 day ago
The weights are literally a binary blob.
Comment by WithinReason 1 day ago
Comment by HPsquared 1 day ago
Comment by ungovernableCat 23 hours ago
Comment by HPsquared 23 hours ago
Comment by ungovernableCat 23 hours ago
Comment by halJordan 1 day ago
Comment by anon373839 1 day ago
Note also that software is copyrightable and model weights aren’t (in the US anyway).
Comment by croemer 1 day ago
One can equally argue that firmware is just settings for the CPU.
If weights aren't copyrightable then doesn't this argue against the idea of them being able to have the quality of open-sourceness? Meanwhile the training code could be copyrightable.
Comment by anon373839 1 day ago
The weights are the asset that makes it useful, but I don’t think 40T tokens of pre-training data should be required to call the model itself open source when you can inspect every line of code in the model without that, as well as instantiate and run the model with randomly initialized weights.
Comment by inigyou 1 day ago
Comment by croes 1 day ago
Comment by solarkraft 1 day ago
Comment by stavros 1 day ago
Comment by charcircuit 1 day ago
>a term that it seems nearly everyone has agreed is appropriate
Models being considered open source even if the original training code / data is not released also is something almost everyone has agreed to be appropriate.
Comment by dietr1ch 1 day ago
It's the 2nd time I hear this argument and I'm already fed up with it
Is it the preferred way only because training is expensive? It's like saying binaries are the preferred way of modifying program because you can't afford to have a fast enough machine to compile it yourself.
Most people don't have resources to compile their own browser, but what makes some browsers open is access to the source.
Maybe it's the preferred way because the people sharing models are themselves working with weights and no data?
Comment by NitpickLawyer 1 day ago
No, it's the preferred way because that's literally how you train it. Contrary to popular misconceptions, you don't "compile" data into weights. You initialize a model (based on architecture, config, etc) and then you modify it via training. But crucially they (i.e. model creators) modify it the same way (technically speaking) as you would. That's what the license grants you. Nothing less, nothing more. The "how" as in knowhow has never been something covered by a license.
Open-weight is something dreamt up by people misunderstanding the basics of model creation and training, and having ideological biases against AI and/or LLMs. It is what it is, but you should know that you are technically wrong. A model released under an open source license (Apache, MIT, etc) is an open source model. Because the weights are the source of the models. Training is not "compilation". Training is the "how" as in knowhow to modify the model. Training deals with values. Source deals with everything, including values.
In the past, if someone would have released a piece of software (say a PID controller algo) w/ hardcoded values, no-one would bat an eye. LLMs are just that, with billions of hardcoded values. Nothing less nothing more.
Comment by teruakohatu 1 day ago
Open source means open source code. Open weight means a binary file dump, not unlike an exe file. There is nothing open source about it.
Its like having a closed source text editor that censors certain words, and an open source text editor that censors certain words.
The latter can easily be recompiled, the former requires reverse engineering. Both may give you a license to use them freely.
Comment by Alpha3031 1 day ago
I do prefer open weights as being more precise (like, is it even really software that has source code in the first place?) but I feel like at this point the ship has sailed somewhat (though if this is something you're willing to spend your time arguing then... moral support I guess?)
Comment by ciupicri 1 day ago
Comment by Muromec 1 day ago
Comment by applfanboysbgon 1 day ago
[1] ...setting aside hardware attestation bullshit, which does need to die in a fire.
Comment by charcircuit 1 day ago
Comment by andy99 1 day ago
I would be very interested to hear someone explain what freedom it is they need the training data to enjoy.
Comment by mlazos 1 day ago
Comment by andy99 1 day ago
They’re not really even being precise. The relevant software freedom, from the FSF is []
The freedom to study how the program works, and change it so it does your computing as you wish (freedom 1). Access to the source code is a precondition for this.
Ported to the model world, this is fulfilled by sharing the weights and implementation. There’s almost nothing that having the training data gets you (other than actually training it). The weights plus a reference implementation let you see all the states to study the behavior, and let you fine tune it to do your bidding (the abliteration etc). The freedom is satisfied.Some might argue that without the training data you couldn’t do some classes of experiments to see how it works, say leave-one-out retraining. I’d argue things like that are not really about the model but about ML research or the class of models, which while interesting is not a free software pre-requisite.
[] https://www.gnu.org/philosophy/free-sw.html#four-freedoms
Comment by j-bos 1 day ago
Comment by nextaccountic 1 day ago
The weights are the output of a program, it's a binary. It's not source.
Comment by shock 1 day ago
Yes. The next time you go to your doctor you should hope he's not being overly precise; or the engineer that builds the bridge; or the software engineer that implemented the embedded software in your insulin pump.
There is no precise thinking without precise terms.
Comment by HPsquared 1 day ago
Comment by ordersofmag 23 hours ago
Now there are reasons you might want to know about the training data when you wouldn't care about the authoring process used by a traditional open-source process. And these get at the reason LLM's are different than traditional software and so maybe our existing definitions of what 'open-source' means aren't a good match for LLM's. Of course there is software associated with LLM's (beyond the weight) -- defining the structure of the particular neural net those weights fit into. In every open-weights model that I'm aware of that software is open source (though trivial).
Comment by bensyverson 23 hours ago
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Comment by logicallee 1 day ago
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Comment by logicallee 1 day ago
When I read your original comment, I was thinking you had just asked it to evaluate the article. (Like just "evaluate this article" or something.)
I don't think anything anyone (or any AI) has ever written or published (including Sol itself) wouldn't be torn apart by the prompt you gave though.
Comment by inferencecoder 1 day ago
Comment by logicallee 18 hours ago
I'm saying everything looks like it does, with the prompt you gave Sol. Go ahead and point the same prompt to anything you don't think has serious flaws and you'll see it would tear it apart.
Comment by IshKebab 1 day ago
Comment by inferencecoder 11 hours ago
Comment by villgax 1 day ago
GPUs. 8× MI355X (TP8) B300 (TP8+DCP8)
Decode tok/s per stream 118 tok/s 172 tok/s
Peak aggregate. 952 tok/s 1,568 tok/s
Peak aggregate per GPU 119 tok/s 196 tok/s
On every row the B300 beat the MI355X
The B200 is being forcefully compared against something which is not gonna fit within it's memory in a single node & not much details about multi-node interconnectivity, disagg or not. As expected of a shoddy slop.
The only point it won is of cost per hour is one aggregation website for rentals, the premium a B300 commands against the $3/hr AMD chip which no provider has in abundance. Never bothered to do TCO of owning the hardware either.
Comment by throwa356262 1 day ago
To the B200’s defence, its numbers are somewhat deflated by the fact that it pays a cross-node all-reduce on the decode critical path (RoCE v2 at ~195 Gb/s) — it’s the only config here that spans two nodesComment by villgax 23 hours ago
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Comment by muragekibicho 1 day ago