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armcat • today at 1:21 PM • 2 replies • view on HN

Something to keep in mind with aggressive quantisation, is that it's been empirically proven [1] that (1) quantisation has non-linear performance behaviour, and (2) generally the peak size-to-performance ratio occurs at 4-bit; anything lower and you will see significant reduction in performance.

Also, I've been playing with speech models for the past 2 years, and for me anything below 8-bit is a huge drop in quality; so quantisation for LLMs and for other bespoke modality models, is not 1:1.

[1] "Reliability Scaling Laws for Quantized Large Language Models", TUM, https://arxiv.org/pdf/2607.10855


Replies

Youden • today at 2:04 PM

I think your leading statement is a bit more authoritative than what the linked paper actually demonstrates. It demonstrates your claimed qualities for specific algorithms, methodologies, and models.

It explicitly says that Quantization-Aware Training is out of scope, may reveal different trends and has potential for extreme quantization. Heavily-quantized model releases today generally use QAT or something similar, so I don't think the paper can be universally applied to modern quants (e.g. [0]).

That said, I don't see any evidence that TFA does any of that so the paper's claims may be quite applicable there.

[0]: https://huggingface.co/vcruz305/DSV4.1-Flash-1017-SAGE-REXL3...

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onlyrealcuzzo • today at 1:24 PM

I imagine that it's just the non-linearity of audio makes it easily apparent how much quantization really matters, and that benchmaxxing is so ingrained in LLMs that if you simply run them through benchmarks, they can do well under quantization, when in reality, they have a similar drop off that they do in audio, it just doesn't slam you in the face at every turn as obviously.