Re:Differential Transformer
by chessgecko on Tuesday October 08, 2024 @08:28PM
(#41783286)
I feel like that blogpost was almost just ragebait for ai researchers. It goes between calling not including the +1 an error (which to me implies it would improve training losses, which it doesn't really https://news.ycombinator.com/item?id=36854613) and saying possibly it could help with some types of quantization (which could very well be true but is a much weaker statement) and the author provides basically no evidence for either.
It's the stereotypical computer scientist who thinks they know something others don't and don't feel the need to prove their claim. Specifically when it disagrees with experts. And unsurprisingly it's been something others have already investigated and even written about. Definitely not all CS people, but it is a stereotype many other fields believe.
I know he's an economist btw. I was also surprised he got a job at anthropic a few months after. I wonder if they're related.
Haven't gone through the paper fully, but just looking at the functional form of their attention, it seems more like a constraint on a standard MHA than an architectural discovery.
Take a vanilla MHA, tie the V projection between consecutive heads, make the output projection subtract consecutive heads, with some fixed prefactor and voila, you're most if not all of the way there.
I've also tested it on many networks and different types of attention and I've yet to see a meaningful improvement (or even an improvement), even in generalization.
It really is the training method...
As to the paper, I'm also still at a big lost and honestly, if reviewing could not accept it. The results look good, but I can't tell why and there's some "black magic" going on here.
Obviously they improved something, but there is nothing in the paper that is convincing me that it is the differential attention. There are too many parameters at play and how am I supposed to know that the difference is by the thing they are proposing. And more importantly, how much it is improved by that specific thing and not by other things.