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Comment on GPT-4-turbo preliminary benchmark results on code-editing

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Back in April it would only generate a handful of tokens per second. The speed improvements for GPT-4 are staggering. I wonder how much of it is because Microsoft is making GPUs rain on OpenAI, and how much of it is due to improvements to the model and its scaffolding.

Perhaps we owe it to Nvidia. Perhaps a huge batch of H100 arrived and the premium models can run there instead of the A100.

H100 + quantisation + algorithmic improvements would be sufficient to explain the speed boost.

If you "have enough compute" available -- which OpenAI definitely does -- the best current technique is to use mixed precision with post-quantisation fine tuning to restore performance. That's most probably how all of the "turbo" models work. Take a model that was initially 16 or 32 bits per parameter during training, quantise it down to a mixture of 4, 8, and 16 bits, and then fix it up with an additional training pass that uses the original full-fat model's predictions as the loss function. With access to the raw parameters, it's possible to do this training such that all of the output weights are considered and adjusted during this phase instead of just the top word. Third parties fine-tuning against GPT4 chats can't do this, even with the collected samples, because they only have individual selected tokens/words instead of the full probability distribution.

To use a graphical term, would it be fair to call that process "dithering"?

Closer to the quantization as seen in JPEG compression.

Based on rumors, it seems that because the demand is so high and supply so short, that Nvidia is having to select who gets the cards. I bet they're likely thinking about who can do the most impactful work and OpenAI would definitely be in the running for the short list of companies who are actually shipping. So I bet OpenAI / Microsoft got a lot of the newest cards.

They’re definitely thinking about impact… to their overall margins.

I think the general (completely speculative and unconfirmed) consensus is that "Turbo" models are somehow quantized, or otherwise modified for much faster and cheaper inference, at the expense of some quality (the definition of "some" is unknown here).

well, that's how it was for GPT-3.5 anyway. The "turbo" flavor was faster and cheaper, but seemed to have slightly worse output (again, this is all going by subjective measurement; it could entirely be the imagination of AI bros)

I agree that this is the case for GPT-3.5, at least subjectively. However, with GPT-4 Turbo, it seems that performance has improved. If they got it to be faster using quantization, then they must have also found a way to offset any resulting performance losses.

They have tons of usage data by now to figure out which queries to devote model capacity to

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