It's not completely out of the question that the 512gb version of M3 Ultra was built for their internal Apple silicon servers powering Private Compute Cloud, but not intended for consumer release, until a compelling use case suddenly arrived.
I don't _think_ this is what happened, but I wouldn't go as far as to call it impossible.
The scenario is that the 512gb M3 Ultra was validated for the Mac Studio, and in volume production for their servers, but a business decision was made to not offer more than a 256gb SKU for Mac Studio.
I don't think this happened, but it's absolutely not "literally impossible". Engineering takes time, artificial segmentation can be changed much more quickly.
This change is mostly just using higher density ICs on the assembly line and printing different box art with a SKU change. It does not take much time, especially if they had planned it as a possible product just in case management changed its mind.
That's absurd. Fabing custom silicon is not something anybody does for a few thousand internal servers. The unit economics simply don't work. Plus Apple is using OpenAI to provide its larger models anyway, so the need never even existed.
My thoughts too. This product was in the pipeline maybe 2-3 years ago. Maybe with LLMs getting popular a year ago they tried to fit more memory but it’s almost impossible to do that that close to a launch. Especially when memory is fused not just a module you can swap.
Your conclusion is correct but to be clear the memory is not "fused." It's soldered close to the main processor. Not even a Package-on-Package (two story) configuration.
I think by fuse I mean't its stuck on to the SOC module, not part of the SOC as I may have worded. While you could maybe still add NANDs later in the manufacturing process, it's probably not easy, especially if you need more NANDs and a larger module which might cause more design problems. The NAND is closer cause the controller is in the SOC. So the memory controller probably would also change with higher memory sizes which would mean this cannot be a last minute change.
