Apple’s M1 Ultra shows the future of computer chips

Apple's M1 Ultra shows the future of computer chips

Apple’s M1 family of Mac processors started with the M1 in 2020 and expanded – literally – with the M1 Pro, M1 Max and M1 Ultra. The M1 Ultra is made up of two M1 Max chips.


If you want to get a glimpse of where CPU activity is headed, check out Apple’s new M1 Ultra processor.

To deliver speed and performance, the consumer electronics giant married two of its oldest M1 Max chips using advancements in a once humble aspect of chip manufacturing called packaging. The packaging no longer only provides a protective case, but now also offers state-of-the-art communication links.

By combining the two chips, Apple’s M1 Ultra offers a mind-blowing 114 billion transistors which make up 20 processing cores and 64 graphics cores. By comparison, AMD Ryzen desktop processors use about a tenth that number of transistors.

The M1 Ultra highlights the progress made by chipmakers keep Moore’s Law alive. A saying in the chip industry, Moore’s Law predicts that the number of transistors on chips doubles every two years. Transistors, the basic circuit elements that process data, have been harder to miniaturize, slowing the progress initially charted by chip pioneer and Intel co-founder Gordon Moore. Advanced packaging offers a new way to increase the number of transistors.

Apple isn’t the only company working on advanced packaging technology to link chips together. Intel, AMD, and Nvidia also have technology for combining multiple chip elements, called arrays or chiplets, into a single, larger processor. The M1 Ultra is arguably the most advanced example of the concept to date, but it won’t be the last.

“You’ll see it in mainstream PCs over time,” said Linley Gwennap, analyst at Tech Insightsnot just Mac Studio systems costing $4,000 and up.

Chip packaging progresses

Packaging has been around as long as chips. Initially, it was a casing to protect a processor and provide it with the electrical connections with the memory, communications and other elements of a computer. Over the years, it has become more and more complex. Now, chipmakers see advanced packaging as crucial to supporting advancements in computing.

The thin lines of these Intel Meteor Lake test chips show how multiple chips make up the entire processor.

Stephen Shankland/CNET

Apple’s UltraFusion, the name of its packaging technology, uses a narrow silicon wafer called an interposer that resides under the two M1 Max chips, connecting them to 10,000 wires that can carry 2.5 terabytes of data per second over a very short distance. This enormous speed is necessary for the chip cores of one die to reach the memory connected to the other. Graphics processing units in particular have an insatiable appetite for data stored in memory.

Interposers have historically been important and expensive. Apple’s custom approach involves a narrower wafer that only crosses the connecting edges of the M1 Max chips.

Intel has developed a similar packaging technology, which it calls Embedded Multi-Die Interconnect Bridge. Intel has yet to use EMIB in chips on the market, but plans to start selling one, a high-end server chip named Sapphire Rapids, later this year. Sapphire Rapids will also use EMIB to link four chips and four large memory modules.

UltraFusion’s more expensive, densely packed wires allow Apple to send data from one die to another about twice as fast as Intel does with Sapphire Rapids, said David Kanter, Real-World Technology Analyst.

Advanced packaging does not solve all problems. At twice the size of an M1 Max, the M1 Ultra consumes about twice as much power and rejects twice as much waste heat, a significant design constraint for computers. Don’t expect to see it in laptops.

Mix and match chiplet assembly is unusual today, but it will become more ordinary. An alliance of nearly all of the world’s top chipmakers should make things easier by developing standardized interfaces that chips use to communicate with each other.

Advanced chip packaging on the way

Apple’s M1 Ultra is just one example of new packaging methods. Larger interposers have been used for years, especially by a very flexible but very expensive type of chip called FPGAs. More recently, he has taken steps towards the mainstream.

Intel’s Sapphire Rapids chip, the next-generation Xeon model for the thousands of servers that pack the data centers of companies like Google and Facebook, will feature a model with four chips married into one. Its chiplets are connected to EMIB, which, like interposers, is a packaging approach called 2.5D because it’s a step beyond the purely two-dimensional packaging used before.

Last year, AMD’s chief executive Lisa Su presented packaging technology which stacks chips on top of each other, called 3D packaging. The first chips using the technology will be the Ryzen 7 5800X3D gaming PC chips expected in the coming weeks. AMD uses its approach, called 3D V-Cache, to link high-speed memory chips into a processor complex for a 15% performance increase over conventional data links.

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Intel also plans to use its 3D stacking technology, called Foveros, with a 2023 PC chip code named Meteor Lake.

EMIB and Foveros also feature in this year’s Ponte Vecchio processor, Intel’s gargantuan graphics, and the AI ​​chip suited for the Department of Energy’s Aurora supercomputer. “Ponte Vecchio is the pinnacle of advanced packaging,” Kanter said.

The high costs of advanced packaging

The Ponte Vecchio also embodies one of the problems with advanced packaging: cost. Chip design, sourcing, alignment, and bonding add complexity and expense to chip manufacturing. This means an additional cost.

AMD Ryzen chip with 3D V-Cache

AMD CEO Lisa Su holds a prototype Ryzen chip with 3D V-Cache memory chips glued on top for faster performance.

AMD video; Screenshot by Stephen Shankland/CNET

Apple’s Mac Studio computer is a good example. It has a starting cost of $1,999 with the M1 Max processor but costs $3,999 with the M1 Ultra. If you want the most powerful version of the chip, with 64 GPUs, add another $1,000 to the price.

“Yes, it’s possible to maintain Moore’s Law, to keep packing more and more transistors into a package, but we’re not doing anything about the cost,” said Gwennap of Tech Insights. “A lot of practical issues need to be resolved before you get to this utopia where you buy lots of chips, plug them together, and everything works.”

For more, take a look at everything Apple announced on Tuesday, including the iPhone SE 3 (here’s how it compares to the 2020 model and why it’s aimed at people “who just want an iPhone”), the new colors of the iPhone 13 and the Updated iPad Air, as well as the Mac Studio and Mac Studio Display. The products arrived with iOS 15.4, the latest update to Apple’s iPhone operating system. You can explore all of these products and more with CNET event recap.