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I am very curious about the production yields of these monsters. Things can go wrong at the cpu, the gpu, the memory etc and any of these reasons will lead a ch

I am very curious about the production yields of these monsters. Things can go wrong at the cpu, the gpu, the memory etc and any of these reasons will lead a chip to the trash bin.

ch_123 5y ago
The M1 Ultra is essentially two M1 Max joined together. I suspect most of the things which can go wrong are at the M1 Max level. I'm sure a certain percentage where fusing two dies together kills one or both dies, but I suspect that's probably a manageable percentage.
sysbot 5y ago
in general the lower yield ones ended up being the lesser model such as M1 Pro using the same die
deergomoo 5y ago
On the latest episode of the Accidental Tech Podcast they were discussing a patent related to this fancy interconnect stuff, and it sounds like not only do they need two fully functioning M1 Max's, but they also need to be adjacent on the wafer. Although I guess at least they can still use the non-defective M1 Max in any pair.
- Applejinx 5y ago
  That would be an interesting approach: don't know if it's what they're doing, but if they're like 'make M1 Ultras predominantly, but then if they break you're making M1 Max with an attached bit that has to be trimmed off', that's pretty ingenious.
  - grishka 5y ago
    I think I've seen a picture of a decapped M1 Max and it had this extra part on the side that never appeared in Apple renders. It was back then when this speculation of it having multiprocessor interconnect started. It was then also confirmed by Asahi Linux people from the software side of things. So no, they don't even bother to trim it off.
grishka 5y ago
This is the reason there are lower-end models of all M1 chips with some CPU and GPU cores disabled. And the M1 Ultra is just two M1 Max glued together.
kllrnohj 5y ago
> Things can go wrong at [..] the memory etc The memory isn't on die. It's just regular lpddr5 but on package. So that's not a yield concern.

I am very curious about the production yields of these monsters. Things can go wrong at the cpu, the gpu, the memory etc and any of these reasons will lead a chip to the trash bin.

ch_123 5y ago

The M1 Ultra is essentially two M1 Max joined together. I suspect most of the things which can go wrong are at the M1 Max level. I'm sure a certain percentage where fusing two dies together kills one or both dies, but I suspect that's probably a manageable percentage.

sysbot 5y ago

in general the lower yield ones ended up being the lesser model such as M1 Pro using the same die

deergomoo 5y ago

On the latest episode of the Accidental Tech Podcast they were discussing a patent related to this fancy interconnect stuff, and it sounds like not only do they need two fully functioning M1 Max's, but they also need to be adjacent on the wafer. Although I guess at least they can still use the non-defective M1 Max in any pair.

Applejinx 5y ago
That would be an interesting approach: don't know if it's what they're doing, but if they're like 'make M1 Ultras predominantly, but then if they break you're making M1 Max with an attached bit that has to be trimmed off', that's pretty ingenious.
- grishka 5y ago
  I think I've seen a picture of a decapped M1 Max and it had this extra part on the side that never appeared in Apple renders. It was back then when this speculation of it having multiprocessor interconnect started. It was then also confirmed by Asahi Linux people from the software side of things. So no, they don't even bother to trim it off.

grishka 5y ago

This is the reason there are lower-end models of all M1 chips with some CPU and GPU cores disabled. And the M1 Ultra is just two M1 Max glued together.

kllrnohj 5y ago

> Things can go wrong at [..] the memory etc The memory isn't on die. It's just regular lpddr5 but on package. So that's not a yield concern.