ml_hardware
Joined 6 years ago
Joined 6 years ago
Here's MPT-30B running in 4-bit precision on CPU :) https://twitter.com/abacaj/status/1673133443339763712?s=20
> Try out our Stable Diffusion code here! > https://github.com/mosaicml/diffusion-benchmark
See the paper here, Figure A28: https://kstatic.googleusercontent.com/files/b068c6c0e64d6f93...
But if your downstream task is simple, like sequence classification, then it may be possible to compress the model without losing much quality.
A pod of gen2-H100s might have 256 GPUs with 40 TB of total memory, and could easily run a 10T param model. So I think we are far from diminishing returns on the hardware side :) The model quality also continues to get better at scale.
Re. reading material, I would take a look at DeepSpeed’s blog posts (not affiliated btw). That team is super super good at hardware+software optimization for ML. See their post on MoE models here: https://www.microsoft.com/en-us/research/blog/deepspeed-adva...
When measured at smaller #s of GPUs which are more realistic, the speedup is somewhere between 3.5x - 6x. See the GTC Keynote video at 38:50: https://youtu.be/39ubNuxnrK8?t=2330
Based on hardware specs alone, I think that training transformers with FP8 on H100 systems vs. FP16 on A100 systems should only be 3-4x faster. Definitely looking forward to external benchmarks over the coming months...
1) NVIDIA will likely release a variant of H100 with 2x memory, so we may not even have to wait a generation. They did this for V100-16GB/32GB and A100-40GB/80GB.
2) In a generation or two, the SOTA model architecture will change, so it will be hard to predict the memory reqs... even today, for a fixed train+inference budget, it is much better to train Mixture-Of-Experts (MoE) models, and even NVIDIA advertises MoE models on their H100 page.
MoEs are more efficient in compute, but occupy a lot more memory at runtime. To run an MoE with GPT3-like quality, you probably need to occupy a full 8xH100 box, or even several boxes. So your min-inference-hardware has gone up, but your efficiency will be much better (much higher queries/sec than GPT3 on the same system).
So it's complicated!
But keep in mind the model won't fit on a single H100 (80GB) because it's 175B params, and ~90GB even with sparse FP8 model weights, and then more needed for live activation memory. So you'll still want atleast 2+ H100s to run inference, and more realistically you would rent a 8xH100 cloud instance.
But yeah the latency will be insanely fast given how massive these models are!
If academics want to do research on expensive cutting-edge tech, they will have to join industrial labs or pool together resources, similar to particle physics or drug discovery research today.
For general tasks like language modeling, we are still seeing predictable improvements (on the next-token-prediction loss) with increasing compute. We will very likely be able to scale things up by 10,000x or so and continue to see increasing performance.
But what does this mean for end users? We are probably going to see sigmoid-like curves, where qualitative features of these models (like being able to do math, or tell jokes, or tutor you in French, or provide therapy, or mediate international conflicts) will suddenly get a * lot * better at some point in the scaling curve. We saw this for simple arithmetic in the GPT-3 paper, where the small <1B param models were terrible at it, and then with 100B scale suddenly the model could do arithmetic with 80%+ accuracy.
Personally I would not expect diminishing returns with increased scale, instead there will be sudden leaps in ability that will be very economically valuable. And that is why Meta and others are so interested in scaling up these models.
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