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What is UltraFusion? Apple M1 Ultra secret feature explained

What is UltraFusion? The M1 Ultra is Apple’s final addition to the first-generation Apple Silicon tech, and it arrives with an incredible secret weapon

Apple’s new M1 Ultra chip is possible thanks to what the company essentially described as a secret feature that already existed within the M1 Max.

The UltraFusion feature is built-in to the M1 Max, but went unmentioned until the Peek Performance event on March 8. Now its time has come and it’ll debut within the new Mac Studio.

Effectively, Apple explained the UltraFusion allows a pair of M1 Max chips to seamlessly work together, making the whole greater than the sum of its parts. That also explains why there’s precisely twice as many CPU and GPU cores present in the M1 Ultra. As Apple announced during the event, there are 20 CPU cores and 64 GPU cores.

It also helps to explain why the new Mac Studio computer containing the M1 Ultra starts at double the price ($3,999) of the model rocking the existing M1 Max version ($1,999) of Apple Silicon.

How does UltraFusion work?

Apple says there’s “never been anything like” the UltraFusion tech it unveiled today. It claims to debut a brand new method for scaling up processing performance, which doesn’t involve the trade-offs of hooking a pair of chips up to a motherboard. Instead, UltraFusion uses a “silicon interposer that connects the chips across more than 10,0000 signals,” Apple says.

This not only overcomes traditional downsides, like an uptick in latency, increased power consumption and reduced bandwidth, it gives all of those factors a significant boost, without developers having to rewrite any code because the software recognises the whole array as a single chip.

Apple says the technology provides “a massive 2.5TB/s of low latency, inter-processor bandwidth — more than 4x the bandwidth of the leading multi-chip interconnect technology.”

Trusted Take

While there was no M2 announcement during the Peek Performance event, the M1 Ultra seemed to make up for that, and then some. Apple’s focus on serving its power Mac users has been revived in recent years and the long-awaited Mac Pro revamp is still to come. One has to wonder whether the departure of Sir Jony Ive – with his obsession with getting rid of ports – was holding the potential of the Mac back all along?

Will you be splashing out on the new Apple Studio Mac with M1 Ultra? Let us know @trustedreviews on Twitter.

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