Arm’s New Programme for Custom Chips

With the financial muscle of a new parent, Arm is adapting to competition

Last week, Arm made several intellectual property announcements unveiling its new chipset core designs, including the Arm Cortex-A78 and Cortex-X1 CPUs, Mali-G78 GPU and the Ethos-N78 neural processor. A lot has been written about the specifications and performance of these cores, so I want to focus instead on why Arm’s Cortex-X1 and supporting Cortex-X Custom programme are important. Let’s take a look at what the announcements mean, the market forces taking Arm in a new direction and the implications for its customers.

Arm’s Cortex-X Custom is a new design programme that promises a fresh level of performance for smartphones and large-screen devices. The Cortex-A78 will be Arm’s premium “off the shelf” core, but the new programme offers customers another option: it allows for more flexibility in customization and differentiation, taking performance to heights not reachable with other Arm cores. Arm claims that the Cortex-X1, which is the first fruit of the custom programme, offers an increase of 30% in peak performance over its previous flagship core, the Cortex-A77.

Arm is essentially promising to raise the bar for customization beyond the traditional road map of its Cortex products. To explain why this is significant we need to understand the options available to customers today.

For those wanting maximum control over their designs, an architectural licence provides maximum flexibility and control. This gives a licensee rights to use the Arm architecture with full control in the design of the core. The best example of this today is Apple with its A series chips, but the likes of Qualcomm, Samsung and others have also used the approach. The downside is that the added control and flexibility comes at significant research and development cost. So, the licensee must be confident that the resulting design will bring a clear performance gain and differentiation.

This has become increasingly difficult in recent years and has pushed companies such as Qualcomm away from custom core design — at least for smartphones — in favour of semicustom development using stock Arm cores and the Built on Arm Cortex initiative. Qualcomm has done so with its Kryo cores in several iterations of its flagship Snapdragon 8 series. As Arm’s own Cortex intellectual property became increasingly competitive, it became more difficult to deliver a meaningful performance advantage through custom development that justified the higher costs.

Samsung is still struggling in this area, with benchmarks consistently showing that its custom cores in its premier Exynos 990 chip fall short of most of its rivals. This has even led to smartphone customers starting a petition to get Samsung to use Qualcomm silicon in all variants of its Galaxy S smartphones.

Arm’s Cortex-X Custom programme is designed to replace the Built on Arm Cortex initiative and offer more room for customization to meet customer requirements, while maintaining efficiencies in design, cost and time to market. Paul Williamson, vice president and general manager of Arm’s Client Business group, succinctly describes it as an “AMG tuning shop for Mercedes engines”.

Licensees will be hoping that the new programme better balances cost and flexibility in customization. I expect that Qualcomm, Samsung (which has already pledged its support), MediaTek and others will be at the front of the queue. This should enable a broader variety of designs that can serve an increasingly segmented market, particularly as Arm penetrates the PC silicon market.

Arm’s move should also allow it to narrow the gap in CPU performance with Apple. Although CPU performance is only one factor in a highly integrated system-on-chip design, Apple’s A series designs have nonetheless consistently outperformed the competition. I believe this was a leading reason for the birth of Cortex-X Custom. Licensees have needed a mechanism to more effectively differentiate and compete.

In response, increased resources under SoftBank ownership have finally enabled Arm to develop multiple microarchitectures in parallel, for example Cortex, Neoverse (for servers) and now Cortex-X Custom.

As Arm courts an ever-broadening range of hardware with huge variance in power and performance needs, to suit a broad range of uses on mobile phones as well as consumer and industrial IoT devices, the company has had to acknowledge the need for more investment for new architectures, tools and business models. The launch of its new flexible access programme giving start-ups exceptional free access is a further sign that Arm recognizes the need to adapt its business in the face of competition, notably from the open-source approach of RISC-V architecture.

Not everyone was enamored by SoftBank’s move to acquire Arm, and the jury is still out on how successful the acquisition will prove to be for either company. But the financial backing of its new parent is giving Arm the crucially important base to adapt, innovate and grow.