The most interesting change for the M5 Pro and Max is Apple moving to a bonded chiplet strategy from a single monolithic die.

> The tech giant says the chips are engineered around its new Fusion Architecture, an advanced design that merges two dies into a single, high-performance system on a chip (SoC), which includes a powerful CPU, scalable GPU, Media Engine, unified memory controller, Neural Engine, and Thunderbolt 5 capabilities.

https://techcrunch.com/2026/03/03/apple-unveils-m5-pro-and-m...

They also replaced the efficiency cores on the CPU chiplet with a new higher performance design.

> The CPU now features six “super cores,” which is Apple’s term for its highest-performance cores, alongside 12 all-new performance cores. Collectively, the CPU boosts performance by up to 30% for pro workloads.