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Google's First Tensor Processing Unit: Architecture

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21–30 of 197 posts

Re: Google's First Tensor Processing Unit: Architecture

#21

Sigh...learning about TPUs a decade ago made me invest heavily in $GOOG for the coming AI revolution...got that one 100% wrong. +400% over 10 years isn't bad but I can't help but feel shortchanged seeing nvidia/etc

I don't think anybody in 2014 believed that the performance of GPT-4/Claude Opus/... was 10 years away. 25 years maybe, 50 years probably, but not 10.

Re: Google's First Tensor Processing Unit: Architecture

#22
post #8

Earlier quoted context omitted.

It's branding (see: TensorFlow); also, pretty much anything (linear) you would do with an arbitrarily ranked tensor can be expressed in terms of vector ops and matmuls

"Fixed-Function Matrix Accelerator" just doesn't have the same buzzy ring to it.

It’s the perfect name for my next EDM SoundCloud mix, though.

Re: Google's First Tensor Processing Unit: Architecture

#23
post #10

Earlier quoted context omitted.

Thanks for the background! I still don’t think it’s appropriate to call a batch of matrices a tensor.

You'd hate particle physics then. "Spin" and "action" and so on are terrible names, but scientists live with them, because convention. Convention dominates most of what we do. I'm not sure there's a good way around this. Most conventions suck, but they were established back before there was a clear idea of what the best long-term convention should be.

At least in physics you can understand how the terms came about historically, where at some point they made sense. But “tensor” here, as note in sibling comments, seems to have been chosen primarily for marketing reasons.

Re: Google's First Tensor Processing Unit: Architecture

#24
post #6
post #3

Earlier quoted context omitted.

If nothing else, the term "tensor" is shorter than "vectors and matrices," and then has the added benefit of representing n-dimensional arrays.

How is that an added benefit if the hardware doesn’t actually support n-dimensional arrays (other the n = 1 and 2)? And, strictly speaking, a vector can be considered a 1x n (or n x1) matrix, so Matrix Processing Unit would have been fine.

At the end of the day all the arrays are 1 dimensional and thinking of them as 2 dimensional is just an indexing convenience. A matrix multiply is a bunch of vector dot products in a row. Higher tensor contractions can be built out of lower-dimensional ones, so I don't think it's really fair to say the hardware doesn't support it.

Re: Google's First Tensor Processing Unit: Architecture

#25
post #12

Earlier quoted context omitted.

I know what a tensor is mathematically. However, as far as I can see, ML isn’t based on tensor calculus as such.

Something similar happens on Wikipedia, where topics that use math inevitably get explained in the highest level math possible. It makes topics harder to understand than they need to be.

As a helpful Wiki editor just trying to make sure that we don't lead people astray, I've made some small changes to clarify your statement:

In the virtual compendium of Wikipedia, an extensive repository of human knowledge, there is a discernible proclivity for the hermeneutics of mathematically-infused topics to be articulated through the prism of esoteric and sophisticated mathematical constructs, often employing a panoply of arcane lexemes and syntactic structures of Greek and Latin etymology. This phenomenon, redolent of an academic periphrasis, tends to transmute the exegesis of such subjects into a crucible of abstruse and high-order mathematical discourse. Consequently, this modus operandi obfuscates the intrinsic didactic intent, thereby precipitating an epistemological chasm that challenges the layperson's erudition and obviates the pedagogical utility of the exposition.

Re: Google's First Tensor Processing Unit: Architecture

#26
post #12
post #9

Earlier quoted context omitted.

Tensor is from mathematics and was popularized over a century ago.

I know what a tensor is mathematically. However, as far as I can see, ML isn’t based on tensor calculus as such.

multidimensional arrays are multilinear mappings, and that is how they are used in ml usually. it seems fine to me

Re: Google's First Tensor Processing Unit: Architecture

#27
post #6
post #3

Earlier quoted context omitted.

If nothing else, the term "tensor" is shorter than "vectors and matrices," and then has the added benefit of representing n-dimensional arrays.

How is that an added benefit if the hardware doesn’t actually support n-dimensional arrays (other the n = 1 and 2)? And, strictly speaking, a vector can be considered a 1x n (or n x1) matrix, so Matrix Processing Unit would have been fine.

it’s an abstraction, just like 2d arrays

Re: Google's First Tensor Processing Unit: Architecture

#28

Sigh...learning about TPUs a decade ago made me invest heavily in $GOOG for the coming AI revolution...got that one 100% wrong. +400% over 10 years isn't bad but I can't help but feel shortchanged seeing nvidia/etc

+400% over 10 years isn't bad.

It’s almost 15% per year, quite a lot.

Re: Google's First Tensor Processing Unit: Architecture

#29
On the podcast interview now Groq CEO Jonathon Ross did[1] he talked about the creation of the original TPUs (which he built at Google). Apparently originally it was a FPGA he did in his 20% time because he sat near the team who was having inference speed issues.

They got it working, then Jeff Dean did the math and the decided to do an ASIC.

Now of course Google should spin off the TPU team as a separate company. It's the only credible competition NVidia has, and the software support is second only to NVidia.

[1] https://open.spotify.com/episode/0V9kRgNS7Ds6zh3GjdXUAQ?si=q...

Re: Google's First Tensor Processing Unit: Architecture

#30
post #10

Earlier quoted context omitted.

I was confused as hell for a long time when I first got into ML, until I figured out how to think about tensors in a visual way. You're right: fundamentally ML is about vector and matrix operations (1D and 2D). So then why are most ML programs 3D, 4D, and in a transformer sometimes up to 6D (?!) One reasonable guess is that the third dimension is time. Actually not. It turns out that time is pretty rare in ML, and it…

Thanks for the background! I still don’t think it’s appropriate to call a batch of matrices a tensor.

why not? multilinear mappings can be represented by “batches of matrices” and that’s all that a tensor is
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