Live data from Hacker News

Mistral "Mixtral" 8x7B 32k model [magnet]

twitter.com

51–60 of 255 posts

Re: Mistral "Mixtral" 8x7B 32k model [magnet]

#51
post #19

Earlier quoted context omitted.

> 96GB of weights. You won't be able to run this on your home GPU. This seems like a non-sequitur. Doesn't MoE select an expert for each token? Presumably, the same expert would frequently be selected for a number of tokens in a row. At that point, you're only running a 7B model, which will easily fit on a GPU. It will be slower when "swapping" experts if you can't fit them all into VRAM at the same time, but it shou…

Someone smarter will probably correct me, but I don’t think that is how MoE works. With MoE, a feed-forward network assesses the tokens and selects the best two of eight experts to generate the next token. The choice of experts can change with each new token. For example, let’s say you have two experts that are really good at answering physics questions. For some of the generation, those two will be selected. But lat…

One viable strategy might be to offload as many experts as possible to the GPU, and evaluate the other ones on the CPU. If you collect some statistics which experts are used most in your use cases and select those for GPU acceleration you might get some cheap but notable speedups over other approaches.

Re: Mistral "Mixtral" 8x7B 32k model [magnet]

#52
post #36
post #30

Earlier quoted context omitted.

You can, wait for a 4-bit quantized version

I only have a RTX 3070 with 8GB VRam. It can run quantized 7B models well, but this is 8 x 7B. Maybe an RTX 3090 with 24GB VRAM can do it.

It would be very tight. 8x7B 24GB (currently) has more overhead than 70B.

Its theoretically doable, with quantization from the recent 2 bit quant paper and a custom implementation (in exllamav2?)

EDIT: Actually the download is much smaller than 8x7B. Not sure how, but its sized more like a 30B, perfect for a 3090. Very interesting.

Re: Mistral "Mixtral" 8x7B 32k model [magnet]

#56
post #36
post #30

Earlier quoted context omitted.

You can, wait for a 4-bit quantized version

I only have a RTX 3070 with 8GB VRam. It can run quantized 7B models well, but this is 8 x 7B. Maybe an RTX 3090 with 24GB VRAM can do it.

Napkin math: 7x(4/8)x8 is 28GB, and q4 uses a little more than just 4 bits per param, and there’s extra overhead for context, and the FFN to select experts is probably more on top of that.

It would probably fit in 32GB at 4-bit but probably won’t run with sensible quantization/perf on a 3090/4090 without other tricks like offloading. Depending on how likely the same experts are to be chosen for multiple sequential tokens, offloading experts may be viable.

Re: Mistral "Mixtral" 8x7B 32k model [magnet]

#57
In other llm news, Mistral/Yi finetunes trained with a new (still undocumented) technique called "neural alignment" are blasting other models in the HF leaderboard. The 7B is "beating" most 70Bs. The 34B in testing seems... Very good:

https://huggingface.co/fblgit/una-xaberius-34b-v1beta

https://huggingface.co/fblgit/una-cybertron-7b-v2-bf16

I mention this because it could theoretically be applied to Mistral Moe. If the uplift is the same as regular Mistral 7B, and Mistral Moe is good, the end result is a scary good model.

This might be an inflection point where desktop-runnable OSS is really breathing down GPT-4's neck.

Re: Mistral "Mixtral" 8x7B 32k model [magnet]

#58
post #17

Earlier quoted context omitted.

> Presumably, the same expert would frequently be selected for a number of tokens in a row In other words, assuming you ask a coding question and there's a coding expert in the mix, it would answer it completely.

yes I read that. do you think it's reasonable to assume that the same expert will be selected so consistently that model swapping times won't dominate total runtime?

No idea TBH, we'll have to wait and see. Some say it might be possible to efficiently swap the expert weights if you can fit everything in RAM: https://x.com/brandnarb/status/1733163321036075368?s=20

Re: Mistral "Mixtral" 8x7B 32k model [magnet]

#59
Hot take but Mistral 7B is the actual state of the art of LLM's.

ChatGPT 4 is amazing yes and i've been a day 1 subscriber, but it's huge, runs on server farms far away and is more or less a black box.

Mistral is tiny, and amazingly coherent and useful for it's size for both general questions and code, uncensored, and a leap i wouldn't have believed possible in just a year.

I can run it on my Macbook Air at 12tkps, can't wait to try this on my desktop.

Re: Mistral "Mixtral" 8x7B 32k model [magnet]

#60
post #36
post #30

Earlier quoted context omitted.

You can, wait for a 4-bit quantized version

I only have a RTX 3070 with 8GB VRam. It can run quantized 7B models well, but this is 8 x 7B. Maybe an RTX 3090 with 24GB VRAM can do it.

Once on llama.cpp, it will likely run on CPU with enough RAM, especially given that the GGUF mmap code only seems to use RAM for the parts of the weights that get used.
Post reply on HN