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Quantized Llama models with increased speed and a reduced memory footprint

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Re: Quantized Llama models with increased speed and a reduced memory footprint

#31
post #19

Earlier quoted context omitted.

Not in production, but I've used a 3B model to test a local LLM application I'm working on. I needed a full end-to-end request/response and it's a lot faster asking a 3B model than an 8B model. I could setup a test harness and replay the responses... but this was a lot simpler.

If for testing then why not just mock the whole thing for ultimate performance ... ?

Probably faster to use off the shelf model with llama.cpp than to mock it

Re: Quantized Llama models with increased speed and a reduced memory footprint

#32

Earlier quoted context omitted.

I don’t get the comment. For one I’m excited for developments in the field. Not afraid it will “replace me” as technology has replaced me multiple times over. I’m looking towards working with these models more and more.

No, I meant that a lot of us are working very fast on a pre-launch product, implementing some cutting edge ideas using e.g. the incredible speedup in a small fast inference model like quantized 3B in combination with other tools, and I think there's quite a bit of paranoia out there that someone else will beat you to market. And so not a lot of sharing going on in the comments. At least not as much as previously, and…

Ok, thank you for pointing that out.

I’m focused on making models play nice with each other rather than building a feature that relies on it. That’s where I see the more relevant work being. Why such news are exciting!

Re: Quantized Llama models with increased speed and a reduced memory footprint

#33

May I ask if anyone has successfully used 1B and 3B models in production and if yes, in what use cases? I seem to be failing even in seemingly simpler tasks such as word translation or zero-shot classification. For example, they seem to not care about instructions to only write a response and no explanation, thus making it impossible to use them in a pipeline :/

For me, it was almost random if I would get a little spiel at the beginning of my response - even on the unquantized 8b instruct. Since ollama doesn’t support grammars, I was trying to get it to work where I had a prompt that summarized an article and extracted and classified certain information that I requested. Then I had another prompt that would digest the summary and spit out a structured JSON output. It was much better than trying to do it in one prompt, but still far too random even with temperature at 0. Sometimes the first prompt misclassified things. Sometimes the second prompt would include a “here’s your structured output”.

And Claude did everything perfectly ;)

Re: Quantized Llama models with increased speed and a reduced memory footprint

#34

Does anyone know why the most common method to speed up inference time is quantization? I keep hearing about all sorts of new methods but nearly none of them is implemented in practice (except for flash attention).

Because the way LLMs work is more-or-less "for every token, read the entire matrix from memory and do math on it". Math is fast, so if you manage to use only half the bits to store each item in the matrix, you only have to do half as much work. Of course, sometimes those least-significant-bits were relied-upon in the original training.

Re: Quantized Llama models with increased speed and a reduced memory footprint

#35

[flagged]

I mean, this outcome of LLMs is expected and the frequency of LLM drops are too fast, and definitely too fast to wait for Meta to do an annual conference with a ton of hype, and furthermore these things are just prerequisites for a massive lemming rush of altering these models for the real fun, which occurs in other communities

Re: Quantized Llama models with increased speed and a reduced memory footprint

#36

May I ask if anyone has successfully used 1B and 3B models in production and if yes, in what use cases? I seem to be failing even in seemingly simpler tasks such as word translation or zero-shot classification. For example, they seem to not care about instructions to only write a response and no explanation, thus making it impossible to use them in a pipeline :/

Yes, I've used the v3.2 3B-Instruct model in a Slack app. Specifically using vLLM, with a template: https://github.com/vllm-project/vllm/blob/main/examples/tool...

Works as expected if you provide a few system prompts with context.

Re: Quantized Llama models with increased speed and a reduced memory footprint

#37
So SpinQuant learns a rotation for activations and weights that, to my understanding, "smear" the outlier weights out so you don't get extreme values in any one weight.

Random anecdote warning - In the old days, before vector search became AI and everyone and their dog offered a vector database, I had a task that required nearest neighbour search in a decent amount of high-dimensional vectors.

I tried quantizing them to bit vectors in an index and scanning through it to get an initial set of candidates. Performance was actually quite decent - reading through RAM linearly is fast! But the selectivity wasn't great.

Somewhere along the way I found this paper[1] that iteratively finds a rotation to apply before quantization to reduce the quantization error. Very similar goal to SpinQuant, but focused on bit quantization only.

As it turns out the 'random rotation' baseline they benchmark against worked great for my use case, so I never tried implementing the fancier algorithm. But it's a pretty rare day at work that "apply a random rotation matrix to a 128-dimensional vector" is the solution to my problem.

[1] https://ieeexplore.ieee.org/abstract/document/6296665 / https://slazebni.cs.illinois.edu/publications/ITQ.pdf

Re: Quantized Llama models with increased speed and a reduced memory footprint

#38
post #26

May I ask if anyone has successfully used 1B and 3B models in production and if yes, in what use cases? I seem to be failing even in seemingly simpler tasks such as word translation or zero-shot classification. For example, they seem to not care about instructions to only write a response and no explanation, thus making it impossible to use them in a pipeline :/

3B models are perfectly capable, I've had great luck with Phi 3.5. > For example, they seem to not care about instructions to only write a response and no explanation You need to use tools to force the model to adhere to a schema. Or you can learn to parse out the part of the response you want, both work. You'll also need to make good use of robust examples in your initial prompt, and give lots of examples of how you…

I wonder if CUE can help the situation in similar fashion to the DSL methods that you've described in your blog post [1]. After all CUE fundamentals are based on feature structure from the deterministic approach of NLP unlike LLM that's stochastic NLP [2],[3]. Perhaps deterministic and non-deterministic approaches is the potent combination that can effectively help reduce much of the footprint to get to the same results and being energy efficient in the process.

[1] Cue – A language for defining, generating, and validating data:

https://news.ycombinator.com/item?id=20847943

[2] Feature structure:

https://en.m.wikipedia.org/wiki/Feature_structure

[3] The Logic of CUE:

https://cuelang.org/docs/concept/the-logic-of-cue/

Re: Quantized Llama models with increased speed and a reduced memory footprint

#39

May I ask if anyone has successfully used 1B and 3B models in production and if yes, in what use cases? I seem to be failing even in seemingly simpler tasks such as word translation or zero-shot classification. For example, they seem to not care about instructions to only write a response and no explanation, thus making it impossible to use them in a pipeline :/

Qwen2.5 3b is very very good.

Re: Quantized Llama models with increased speed and a reduced memory footprint

#40
post #26

Earlier quoted context omitted.

3B models are perfectly capable, I've had great luck with Phi 3.5. > For example, they seem to not care about instructions to only write a response and no explanation You need to use tools to force the model to adhere to a schema. Or you can learn to parse out the part of the response you want, both work. You'll also need to make good use of robust examples in your initial prompt, and give lots of examples of how you…

I wonder if CUE can help the situation in similar fashion to the DSL methods that you've described in your blog post [1]. After all CUE fundamentals are based on feature structure from the deterministic approach of NLP unlike LLM that's stochastic NLP [2],[3]. Perhaps deterministic and non-deterministic approaches is the potent combination that can effectively help reduce much of the footprint to get to the same resu…

On my LinkedIn post about this topic someone actually replied with a superior method of steering LLM output compared to anything else I've ever heard of, so I've decided that until I find time to implement their method, I'm not going to worry about things.

tl;dr you put into the prompt all the JSON up until what you want the LLM to say, and you set the stop token to the end token of the current JSON item (so ',' or '}' ']', whatever) and you then your code fills out the rest of the JSON syntax up until another LLM generated value is needed.

I hope that makes sense.

It is super cool, and I am pretty sure there is a way to make a generator that takes in an arbitrary JSON schema and builds a state machine to do the above.

The performance should be super fast on locally hosted models that are using context caching.

Eh I should write this up as a blog post, hope someone else implements it, and if not, just do it myself.

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