Apple Could ‘Stack’ Multiple M1 Max Chips to Create 128-Core GPU Combos

The M1 Max is already easily the most insanely powerful consumer chip ever made, but it turns out that Apple may be planning to do more with its latest silicon than we first imagined.

New images discovered by Vadim Yuryev of Max Tech reveal that Apple has designed its M1 Max chip to be “stacked” with other M1 Max chips, creating an even more powerful combo chip.

According to Tom’s Hardware, the images show an interconnect bus that’s designed for Multi-Chip-Module (MCM) scaling.

Essentially, that would allow Apple to stack multiple M1 Max chips into a “chiplet” design, effectively doubling or quadrupling the capabilities of the M1 Max chip.

This lines up with rumours we’ve previously heard that Apple doesn’t plan to wait to build another generation of its M-series chips before it releases a more powerful Apple Silicon Mac Pro. Instead, insiders have suggested that Apple is planning to use a variant of the M1 Max chip with at least two dies — and it looks like the M1 Max has already been built to handle this, and more.

Basically, Apple could scale the M1 Max up into an “M1 Max Duo” with twice the cores, or even an “M1 Max Quadra” (or “M1 Max Ultra”) with four times the power.

In other words, Apple already has the capability to create a chip module with a 40-core CPU, 128-core GPU, and 256GB of RAM, which also works out to a combined 228 billion transistors across four dies.

To be clear, this isn’t simply a matter of gluing the chips together — a few interconnecting components would be required to handle the inter-chip communications. However, that’s trivial compared to designing a whole new next-generation SoC, and it’s clear from these latest photos that Apple is already preparing for this scenario.

Notably, the M1 Pro does not have the same interconnect bus, which suggests that Apple is only planning to use this to take the M1 Max to the next level. This is somewhat understandable since the purpose of this would be to meet the demands of very high-end pro applications that require performance that only a fully tricked-out Mac Pro can deliver.

The M1 Max Duo would be the simplest undertaking, since this only involves connecting two chips, while an M1 Max Quadra would be more complicated, possibly requiring an added I/O die to sit between the two M1 Max Duo pairs.

However, as Tom’s Hardware notes, even a pair of M1 Max dies combined into an M1 Max Duo chip would provide up to 20 CPU cores and 64 GPU cores, while also doubling the system memory to 128GB, and the memory bandwidth to 800 GB/s.

The concept isn’t entirely a new one, as custom chip designs have been using stacked MCM scaling for some time. In fact, that’s the basis of Intel’s new Ponte Vecchio AI chip, although the rival chipmaker appears to be pushing that one right to the outer limits of what’s possible.

The so-called M1 Max Duo and M1 Max Quadra chips would likely be considerably more expensive, since there would still be development costs involved in putting them together. However, it’s safe to say they’d be designed to appeal to those customers who don’t bat an eye at shelling out $52,000 on a fully loaded Mac Pro.

[The information provided in this article has NOT been confirmed by Apple and may be speculation. Provided details may not be factual. Take all rumors, tech or otherwise, with a grain of salt.]