Comment by danpalmer
8 hours ago
I'd imagine that the 22GB was decided through modelling various scenarios. For a start, it's not just a 4GB current model, it's 2x4GB to be able to update it without needing time when the computer is without a model, that's up to 8GB.
Then it's possible the model you get will scale with the CPU/GPU/RAM available, so if you have a 12GB GPU you probably get a better model, perhaps that's a 10-11GB model? At 2x that's 22GB.
Then consider that a machine is not static, GPUs/hardware come and go, VRAM allocation in integrated graphics changes, etc. You end up with just needing to pick a number and not confuse users.
(Former Chrome built-in AI team member here.)
This is part of it, and also we just didn't want to use up the last of the user's disk space! It's disrespectful to use up 3 GB if the user only has 4 GB left; it's sketchy if the user only has 10 GB. At 22 GB, we felt there was more room to breathe.
One could argue that users should have more agency and transparency into these decisions, and for power users I agree... some kind of neato model management UI in chrome://settings would have been cool. But 99% of users would never see that, so I don't think it ever got built.