Apple M5 silicon could ditch unified memory for split CPU and GPU designs

Rumor mill: Reports are emerging about some wild changes coming to Apple’s next-gen M5 chips. One of these is the lineup ditching the unified architecture that’s been a signature of Apple silicon so far. Instead, the CPU and GPU will use separate memory pools.

The claim comes from analyst Ming-Chi Kuo. He says that all M5 variants, including the base M5, M5 Pro, M5 Max, and M5 Ultra, will be fabricated on TSMC’s advanced 3nm N3P process node. That’s a change from the current M4 and A18 Bionic chips that use the slightly older N3E node.

The potential split CPU/GPU architecture is definitely the biggest surprise, though. Since the M1’s debut, Apple silicon has used a unified memory pool shared between the CPU and GPU cores. This unified memory access (UMA) design is widely credited with the incredible performance-per-watt efficiency we’ve seen on MacBooks. If these rumors hold, that design won’t be long for this world. While separating the CPU and GPU memory spaces adds some complexity, it could also unlock performance gains in certain workloads.

To pull off this change, Apple is reportedly turning to TSMC’s server-grade 2.5D packaging tech called System on Integrated Chips-Molding Horizontal (SoIC-mH). SoIC is TSMC’s take on 3D stacking and hybrid wafer bonding, which enables ultra-dense connections between two chips. The “mH” variant Apple is using allows them to glue the separate dies horizontally onto the package rather than a vertical 3D stack.

This advanced packaging allows for those split designs while promising better yields and superior thermal performance.

Kuo says that the new packaging approach will particularly benefit Apple’s Private Cloud Compute ambitions. This is what the company calls its cloud intelligence system designed specifically for AI processing.

Ultimately, the M5 lineup is shaping up to be Apple’s most versatile silicon yet. Kuo says that the base M5 will go into mass production in the first half of 2025, meaning it should probably find its way into updated Macs in late 2025. Meanwhile, the M5 Pro/Max variant is expected to enter production in the second half of next year. Lastly, the M5 Ultra is expected to debut in 2026.

Related Content

An interview with YouTube CEO Neal Mohan on rolling out AI tools without upsetting creators, and more; YouTube has paid $70B to partners in the past three years (Stephen Morris/Financial Times)

The GMCI Meme index, which tracks leading memecoins by market cap, delivered 320% returns in 2024, outpacing AI at 91% and the top 30 cryptocurrencies at 88% (The Block)

Alibaba Cloud partners with 01.AI, the Beijing-based AI unicorn founded by former Google China head Kai-Fu Lee, to set up an "industrial large model laboratory" (Ann Cao/South China Morning Post)

Leave a Comment