RISC-V in the Real World: Why Billions of Microcontrollers Are Already Using It
RISC-V: The Open-Source ISA Quietly Powering Billions of Devices
RISC-V (pronounced “risk-five”) is an open-source instruction set architecture (ISA) developed with the goal of providing a royalty-free, flexible alternative to proprietary architectures like ARM and x86. Originally conceived in 2010 at the University of California, Berkeley, it was designed to simplify computing while still supporting a wide range of applications, from small embedded systems to complex data centres. Since then, RISC-V has been managed by RISC-V International, a non-profit organisation that oversees the standardisation and development of the architecture. Its open-source nature and modular design have made it a compelling choice for companies seeking customisable and cost-effective solutions.
What RISC-V is Doing Now: Dominating Embedded Systems and Auxiliary Roles
While much of the recent discussion around RISC-V has focused on its potential to disrupt high-performance computing, the real impact lies in its widespread adoption in embedded systems and auxiliary processors. Billions of RISC-V cores have already been shipped across various industries, including consumer electronics, automotive, and industrial applications. The architecture’s modular approach, which allows companies to implement only the necessary features, makes it especially well-suited for small, specialised tasks in Internet of Things (IoT) and other embedded applications.
For example, many of the latest Android System on Chips (SoCs) include RISC-V cores for managing tasks like power control, display management, and security. These RISC-V cores act as system controllers, performing specific, often invisible functions that are critical to the operation of the device. This use case highlights the real value of RISC-V: it is not necessarily aiming to replace high-performance CPUs in consumer laptops or servers, but rather to handle specialised functions that benefit from a lightweight, efficient, and customisable ISA.
Leveraging RISC-V’s Licensing Flexibility: A Cost-Saving Move for Companies
A key reason for RISC-V’s rapid adoption in these roles is its open-source, royalty-free nature. Unlike ARM or x86, there are no licensing fees or legal constraints tied to RISC-V, allowing companies to integrate the architecture into their products without additional costs. This licensing freedom is particularly advantageous for tasks that require deploying a large number of small, specialised cores. Companies can embed RISC-V cores as auxiliary processors in their hardware, like auxiliary microcontrollers, without incurring the expenses associated with proprietary ISAs.
Take Nvidia, for example, which which started switching to RISC-V cores in it’s proprietary microcontrollers in 2015. These cores handle specific functions such as power management and display control, tasks that are essential for the operation of the microcontroller but don’t directly contribute to its computational performance. By shifting these responsibilities to small RISC-V cores, Nvidia can avoid royalty costs while still achieving the functionality needed. However, for the main computing tasks, Nvidia continues to rely on its proprietary CUDA architecture.
Where RISC-V Shines: Embedded Systems, IoT, and Microcontrollers
The simplicity and flexibility of RISC-V make it an ideal candidate for embedded systems and IoT devices. Unlike general-purpose CPUs that require complex instruction sets, many embedded applications only need basic integer operations, simple memory handling, and a minimal set of instructions. RISC-V’s ability to strip down to just the essential functions makes it suitable for small controllers where minimising size, power consumption, and cost is crucial.
The recent ratification of the RVA23 profile in October 2024 helps address a long-standing challenge: fragmentation within the RISC-V ecosystem. By standardising key ISA extensions, including vector operations, floating-point support, and hypervisor capabilities, the RVA23 profile aims to bring consistency across RISC-V implementations. This unified approach ensures that software targeting RISC-V will work seamlessly across different hardware, further solidifying the architecture’s position in embedded and auxiliary applications.
Limitations and Challenges: Why High-Performance Computing Isn’t RISC-V’s Focus—Yet
While RISC-V has achieved remarkable success in the embedded domain, its journey into high-performance computing remains limited. Most companies are leveraging RISC-V for roles that are largely invisible to end-users, such as embedded controllers and system management tasks. For example, while Nvidia has been incorporating RISC-V into its GPU architectures these cores handle specialised tasks, like power management/system monitoring, and do not perform the heavy lifting required for high-end gaming or data processing.
The reality is that, although RISC-V can be extended to support more advanced features like vector processing, companies are hesitant to adopt it for high-performance designs. Instead, they prefer to keep high-performance architectures proprietary to maintain a competitive edge. The recent ratification of the RVA23 profile brings the architecture closer to being capable of supporting more demanding applications. However, RISC-V still faces an uphill battle to expand its software ecosystem, which is currently much smaller than that of ARM or x86. The path to wider adoption in data centres and high-performance computing will require ongoing development in tools, libraries, and vendor support.
The Future of RISC-V: A Pragmatic Approach to Computing
RISC-V’s strengths lie in its ability to simplify and optimise the design of small, low-power devices while providing companies the flexibility to avoid licensing costs. As more companies incorporate RISC-V cores into their products, its presence in the tech world will continue to grow quietly but steadily. The architecture’s open-source nature fosters innovation, enabling developers to experiment with new designs and contribute to the evolution of computing.
While the prospect of RISC-V taking on high-performance roles remains uncertain, its current trajectory is clear: RISC-V will further increase its market share of the embedded systems, IoT, and auxiliary core markets, where its cost advantages and customisation options bring the most value. As the ecosystem continues to mature and the standards become more unified, it may pave the way for a broader range of applications in the future.
Written by Ilan Goren
Ilan Goren is a computer science student and technology enthusiast, passionate about open-source innovation and emerging tech trends. With a focus on scalable software and embedded systems, Ilan offers insights into how technologies are shaping the future of computing.
