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DeepMind achieves SOTA image recognition with 8.7x faster training

arxiv.org

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Re: DeepMind achieves SOTA image recognition with 8.7x faster training

#11
post #8

The speed improvements are certainly interesting, the performance improvements seem decidedly not. This method has more than 2x the parameters of all but one of the models it was compared against. If I’m off-base here can someone explain?

I don't care how many parameters my model has per se. What I care about is how expensive it is to train in time and dollars. If this makes it cheaper to train better models despite more parameters, that's still a win.

Re: DeepMind achieves SOTA image recognition with 8.7x faster training

#12
post #8

The speed improvements are certainly interesting, the performance improvements seem decidedly not. This method has more than 2x the parameters of all but one of the models it was compared against. If I’m off-base here can someone explain?

I don't care how many parameters my model has per se. What I care about is how expensive it is to train in time and dollars. If this makes it cheaper to train better models despite more parameters, that's still a win.

There's one important caveat, though I agree with your thrust: at GPT-3 scale, cutting params in half is a nontrivial optimization. So it's worth keeping an eye out for that concern.

(Yeah, none of us are anywhere near GPT-3 scale. But I spend most of my time thinking about scaling issues, and it was interesting to see your comment pop up; I would've agreed entirely with it myself, if not for seeing all the anguish caused by attempting to train and deploy billions of parameters.)

Re: DeepMind achieves SOTA image recognition with 8.7x faster training

#13

I was skeptical of the 83%-whatever top-1 accuracy on Imagenet. But someone pointed out that the accuracy increases when the model is pretrained on JFT, google's proprietary 100-million image dataset, the model's accuracy increases to 87%-whatever. That's pretty interesting. It implies that the original accuracy rating might be legit. The concern is that we're chasing the imagenet benchmark as if it's the holy grail,…

> pretraining on JFT increases the accuracy means that the model is generalizing

not necessarily, it may be mostly a bonus of the transfer, especially considering that JFT is that much larger - getting for example the first conv layers kernels to converge to Gabor-like takes time, yet those layers kernels are very similar across the well trained image nets (and there were some works showing that it is optimal in a sense, and that it is one of the reasons it is in our visual cortex) and thus transferrable, and can practically be treated as fixed in the new model (especially if those layers were pretrained on very large model and reached the state of generic feature extraction). I suspect the similar is applicable for the low level feature aggregating layers too.

Re: DeepMind achieves SOTA image recognition with 8.7x faster training

#14
They compare the training latency for different models with a fixed batch size of 32. But if the DeepMind models are several times larger than the comparison models in each latency class, it seems that the comparison models could use larger batch sizes for faster overall training time.

Re: DeepMind achieves SOTA image recognition with 8.7x faster training

#15

I was skeptical of the 83%-whatever top-1 accuracy on Imagenet. But someone pointed out that the accuracy increases when the model is pretrained on JFT, google's proprietary 100-million image dataset, the model's accuracy increases to 87%-whatever. That's pretty interesting. It implies that the original accuracy rating might be legit. The concern is that we're chasing the imagenet benchmark as if it's the holy grail,…

Where are these images from? Are there more?

Re: DeepMind achieves SOTA image recognition with 8.7x faster training

#16
post #2

> 8.7x faster to train This is an achievement but it would be helpful to have put "to train" in the title as this is quite different from efficiency at inference time, which is what often actually matters in deployed applications. From Table 3 on Page 7 it appears to me that NFNet is significantly heavier in the number of parameters than EfficientNet for similar accuracies. For example EffNet-B5 achieves 83.7% with 3…

> It appears to me at first glance that NFNet has not achieved SOTA at inference.

It has, for larger models (F1 vs B7). See Fig 4 in the Appendix.

Re: DeepMind achieves SOTA image recognition with 8.7x faster training

#18

I was skeptical of the 83%-whatever top-1 accuracy on Imagenet. But someone pointed out that the accuracy increases when the model is pretrained on JFT, google's proprietary 100-million image dataset, the model's accuracy increases to 87%-whatever. That's pretty interesting. It implies that the original accuracy rating might be legit. The concern is that we're chasing the imagenet benchmark as if it's the holy grail,…

What safeguards are there or what assurances do we have that JFT is not contaminated with images from (or extremely similar to) the validation set?

Re: DeepMind achieves SOTA image recognition with 8.7x faster training

#19
post #17

eli5 what SOTA image recognition is?

SOTA is 'state of the art'. Image recognition is a task classically appraised by calculating the accuracy on the ImageNet dataset, which requires a system to classify images each as one of 1,000 pre-determined classes.
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