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Comment by linuxftw

2 days ago

That's true only in a vacuum. For example, should I run gpt-oss-20b unquantized or gpt-oss-120b quantaized? Some models have a 70b/30b spread, and that's only across a single base model, where many different models exist at different quants could be compared for different tasks.

Definitely. As a hobbyist, I have yet to put together a good heuristic for better-quant-lower-params vs. smaller-quant-high-params. I've mentally been drawing the line at around q4, but now with IQ quants and improvements in the space I'm not so sure anymore.

  • Yeah, I've kinda quickly thrown in the towel trying to figure out what's 'best' for smaller memory systems. As things are just moving so quickly, whatever time I invest into that is likely to be for nil.

For GPT OSS in particular, OpenAI only released the MoEs in MXFP4 (4bit), so the "unquantized" version is 4bit MoE + 16bit attention - I uploaded "16bit" versions to https://huggingface.co/unsloth/gpt-oss-120b-GGUF, and they use 65.6GB whilst MXFP4 uses 63GB, so it's not that much difference - same with GPT OSS 20B

llama.cpp also unfortunately cannot quantize matrices that are not a multiple of 256 (2880)