[tuvan]

Is it actually 2 different pieces of silicon though? I thought they were 2xM1 Max as a single silicon. Which wouldn't help with defect rates

[addaon]

It is two separate dice, with an EMIB-style interconnect.

[mcronce]

That makes a lot of sense. The Max is still pretty fucking big, but two of those is a lot more manageable than a single monolothic die double the size

[ace2358]

I just listened to the latest atp.fm podcast. I think John said that it actually is two adjacent M1 max dies. The Ultra can’t be made from two random working die. They have to physically be adjacent on the wafer.

I don’t know if that means it’s physically one due though.

[wmf]

Usually dies aren't mirrored on the wafer so I'm calling citation needed on this one.

[ace2358]

Not sure if the counts. I know it’s a patent and it could be anything. But it talks about two adjacent dies being used if they’re good or being split if there is a defect.

https://patents.google.com/patent/US20210217702A1/en?oq=2021...

[wmf]

Thanks for the link. I'm not a lithography expert, but this looks like a Cerebras-style approach at a smaller scale. It might be cheaper than the EMIB/InFo approach since there's no interposer with the associated alignment and thickness issues. In the keynote Apple explicitly said they're using a silicon interposer, which doesn't sound like this patent.