AMD's RDNA 4 GPUs Adopt Modular SoC Architecture

Unlocking Efficiency: AMD's Groundbreaking Modular GPU Design

AMD's Modular Architecture Unveiled at Hot Chips 2025: A Game-Changer for GPU Development

Following the February release of AMD's RDNA 4 graphics cards, including the Radeon RX 9070 XT, the company has just disclosed a significant technological advancement: a sophisticated modular architecture. This revelation came during a comprehensive presentation on RDNA 4 graphics technology at the recent Hot Chips 2025 conference, where AMD shed light on the intricacies of its "modular SoC architecture." This design philosophy aims to facilitate the more economical creation of diverse GPU configurations.

Revolutionizing GPU Creation: The Principles of AMD's Scalable Design

AMD's core objective with RDNA 4 is to establish a foundational GPU SoC design that can be readily expanded to produce larger, more powerful graphics processors. The fundamental SoC incorporates two shader engines and four memory controllers, each accompanied by L3 cache, alongside essential components like the display engine and power management systems. This ingenious design permits the seamless integration of additional shader engines, memory controllers, and cache, all interconnected via Infinity Fabric, allowing for direct scalability. The crucial aspect is that critical elements, such as the display engine and power management, remain consistent across all GPU versions, regardless of size.

A Paradigm Shift: Contrasting AMD's Modular Approach with Conventional GPU Designs

This innovative modularity sharply contrasts with conventional GPU manufacturing, where each GPU variant typically necessitates a unique, custom layout for its various components. Unlike bespoke designs, where even minor additions can demand extensive re-engineering, AMD's strategy ensures that once the base SoC layout is perfected, creating larger GPU iterations simply involves adding pre-designed modules. This significantly accelerates the design and validation phases, reducing the overall time and cost associated with preparing a GPU for fabrication.

Current Implementations and Future Prospects: RDNA 4's Modular Capabilities

In the current RDNA 4 lineup, the Navi 44 GPU, found in the Radeon RX 9060 XT, embodies the base SoC with its two shader engines and four memory controllers. Conversely, the Navi 48 GPU, powering the Radeon 9070 XT, represents the expanded variant, incorporating additional shader engines, memory controllers, and cache. While these GPUs are built on distinct silicon—meaning the smaller unit isn't merely a trimmed version of the larger—the modular engineering greatly enhances development efficiency. Despite the apparent narrow range of RDNA 4 GPUs, the inherent modularity might suggest a broader potential for future generations, although physical limitations on chip size and interconnects could impose boundaries on how extensively this approach can be scaled.

Beyond RDNA 4: Speculation and the Evolution of AMD's GPU Strategy

The implications for AMD's future GPU developments remain a subject of ongoing speculation. While this modular design differs subtly from the chiplet architecture successfully employed in AMD's Ryzen CPUs, it's a noteworthy evolution. After experimenting with chiplets for RDNA 3, AMD reverted to monolithic GPUs for RDNA 4. However, whispers suggest a potential return to chiplets for upcoming generations, possibly under the RDNA 5 or UDNA nomenclature. Rumors circulate about a mid-range AT2 GPU that could serve as a new foundational SoC, potentially combining multiple units to create a high-end AT0, signifying AMD's continued pursuit of innovative, scalable solutions to challenge market leaders.