[wtallis]

> but chip lithography errors (thus, yields) at the huge memory density might be partially driving up the cost for huge memory.

Apple's not having TSMC fab a massive die full of memory. They're buying a bunch of small dies of commodity memory and putting them in a package with a pair of large compute dies. How many of those small commodity memory dies they use has nothing to do with yield.

[jjtheblunt]

Is there a teardown link available for what you wrote? If so, that’s interesting.

[cayleyh]

This has been pretty clear about all Apple chip designs, going back to some of the first A series afaik. They are "unified memory" but not "memory on die", they've always been "memory on package"-- ie. the ram is packaged together with the CPU, often under a single heat spreader, but they are separate components.

Apple's own product shots have shown this. Here's a bunch of links that clearly show the memory as separate. Lots of these modules you can make out the serial or model numbers and look up the manufacturer of them from directly :)

- Side-by-side teardown of M1 Pro vs M2 Pro laptop motherboards showing separate ram chips with discussion on how apple is moving to different type of ram configurations: https://www.ifixit.com/News/71442/tearing-down-the-14-macboo...

- M2 teardown with the chip + ram highlighted: https://www.macrumors.com/2022/07/18/macbook-air-m2-chip-tea...

- Photo of the A12 with separate ram chips on a single "package": https://en.wikipedia.org/wiki/Apple_A12X

- M1 Ultra with heat spreader removed, clearly showing 3rd party ram chips onpackage: https://iphone-mania.jp/news-487859/

[jjtheblunt]

neat! thanks