this post was submitted on 16 Jan 2024
88 points (100.0% liked)

Technology

37735 readers
49 users here now

A nice place to discuss rumors, happenings, innovations, and challenges in the technology sphere. We also welcome discussions on the intersections of technology and society. If it’s technological news or discussion of technology, it probably belongs here.

Remember the overriding ethos on Beehaw: Be(e) Nice. Each user you encounter here is a person, and should be treated with kindness (even if they’re wrong, or use a Linux distro you don’t like). Personal attacks will not be tolerated.

Subcommunities on Beehaw:


This community's icon was made by Aaron Schneider, under the CC-BY-NC-SA 4.0 license.

founded 2 years ago
MODERATORS
you are viewing a single comment's thread
view the rest of the comments
[–] jarfil 1 points 10 months ago

It basically learns shifting the output of each Transformer layer

That would increase inference time, which is something they explicitly avoid.

Check point 4.1 in the paper. W is a weight matrix for a single layer, and the training focuses on finding a ∆W such that the result is fine tuned. The LoRA optimization lies in calculating a ∆W in the form of BA with lower ranks, but W still being a weight matrix for the layer, not its output:

W0 + ∆W = W0 + BA

A bit later:

When deployed in production, we can explicitly compute and store W = W0 + BA and perform inference as usual

W0 being the model's layer's original weight matrix, and W being the modified weight matrix that's being "executed".

the original Transformer stays intact

At training time, yes. At inference time, no.

before you know it you have hundreds and your output quality has degraded irrecoverably.

This is correct. Just not because you've messed with the output of each layer, but with the weights of each layer... I'd guess messing with the outputs would cause a quicker degradation.