Open Source vs. Legacy Giants: A Comparative Guide to RISC-V, ARM and x86

The evolution of computing architectures has profoundly shaped modern electronics, shaping everything from smallest IoT devices to powerful data centers. Among the key players are RISC-V, ARM, and x86, each offering unique strengths and opportunities. For engineers, selecting the right architecture can make or break a project. This blog aims to take a closer look at how these architectures stack up, along with insights into how platforms like CELUS can help streamline design decisions.

Technical Strengths and Adoption

RISC-V’s open-source nature is perhaps its most disruptive quality, followed by the levels of offered customizability. It is allowing companies to innovate without licensing constraints and its adoption is rapidly growing in IoT and consumer electronics, where cost-effectiveness is crucial. In fact, companies working in automotive are investing heavily in alliances and development for future products. Overall, RISC-V is projected to expand by 30% annually until 2027 ^[1].

However, RISC-V’s ecosystem maturity is still a hurdle, with fewer tools and pre-existing libraries compared to ARM and x86. ARM remains dominant in mobile devices and embedded systems and is growing fast in the desktop and server systems, giving it a strong foothold in the market. Its extensive ecosystem, widespread adoption and software support ensure that it remains a leading choice for engineers seeking power-efficient solutions, which started on battery-powered devices and now covers most of them.

x86, while firmly entrenched in PCs and servers, faces cost and efficiency challenges. However, its deep-rooted legacy compatibility and ecosystem maturity still make it indispensable for many high-performance applications. Its architecture is well suited to perform complex operations in fewer clock cycles, and it is this added complexity that tends to consume more power and generate more heat than other options. A double-edged sword.

Thus, broader adoption of RISC-V will likely occur only if larger companies (based on their project needs) begin incorporating it into their architectures, potentially reshaping the market landscape.

Does It Pay to be Open-Source?

Unlike ARM or Intel, RISC-V’s open-source nature allows companies to develop products without paying licensing fees or adopt RISC-V cores from other companies at a much lower fee. This, allied with the flexibility on extending RISC-V cores lets companies customize the instruction set for better performance or power efficiency on specific applications, reducing final costs. The savings on licensing fees make products cheaper, ultimately enabling the creation of smarter, more affordable consumer equipment.

RISC-V’s no-license-fee model is a game-changer for companies looking to lower licensing fee costs and retain more control over their designs. This is particularly appealing for startups and organizations designing custom hardware for niche markets.

ARM’s licensing model offers a different kind of value: access to a mature ecosystem and extensive developer support. While licensing fees can add cost, they also provide a level of reliability and predictability that many companies value, especially in high-end industries like medical and automotive.

x86, as a proprietary architecture, was traditionally hard to license, as it was not developed with the same strategy as ARM. It has been used by Intel, its owner, and AMD over the past decades, and detained an absolute competitive advantage in the early 2000’s. It still dominates markets where performance and software compatibility are non-negotiable.

The Performance vs. Power Consumption Debate

ARM leads in power efficiency, thanks to technologies like big.LITTLE architecture and reduced instruction set architecture (RISC)-based design. This makes it the go-to choice for smartphones, wearables, and other battery-powered devices. Its scalability ensures that ARM processors can also be found in higher-performance domains like automotive and cloud computing.

x86, on the other hand, is synonymous with performance-heavy applications, including gaming PCs, data centers, and scientific computing. However, this comes at the cost of higher power consumption and more complex thermal management. Its more complex instruction set (CISC), allows for more complex instructions in less time. Intel’s hybrid architectures (e.g., Alder Lake) are closing the efficiency gap, but x86 still trails ARM in energy-constrained environments.

RISC-V occupies a middle ground and still has a lot to grow. It is similar to ARM because of its RISC design, which focuses on efficiency and lower power consumption. Its lightweight, customizable architecture allows engineers to optimize for power or performance as needed, adding or removing new instructions without compromising compatibility. However, it’s yet to achieve the extreme efficiency of ARM or the raw performance of x86, particularly in mass-market applications.

How does CELUS fit into all this?

By now you realize that selecting the right architecture involves balancing performance, power, cost, and ecosystem requirements - a task that can be daunting without the right tools. CELUS simplifies this in several ways.

• CUBOs: CUBOs transform traditional datasheets and application notes into actionable, interactive design elements. Engineers can quickly evaluate how a component fits into their design and make adjustments without poring over dense documentation.

• Streamlined Comparisons: CELUS organizes specifications and features into and transform them into structured, CAD-ready schematics, enabling engineers to compare faster architectures like RISC-V, ARM, and x86 side by side.

• Automation and Validation: CELUS automates component selection and validates design choices against technical requirements, reducing the risk of costly errors.

The platform assists in identifying the best architecture for applications, such as IoT devices, enabling engineers to make confident design decisions that align with their goals.

By reducing design complexity, CELUS allows engineers to focus on the trade-offs that matter most, whether it’s the flexibility of RISC-V, the efficiency of ARM, or the performance of x86. The choice, ultimately, is yours.

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[1] BCC Publishing. RISC-V Technology Market Size, Share & Growth Analysis Report. BCC Research LLC. 
RISC-V Technology Market Size, Share & Growth Analysis Report