Cortex A78Edit
The Cortex-A78 is a high-performance central processing unit core designed by Arm Holdings. Introduced in 2020 as the successor to the Cortex-A77, it serves as the mainstream performance pillar in Arm’s Cortex-A family for mobile and embedded systems. The design emphasizes a balance of speed and efficiency, making it a common choice for SoCs used in smartphones, tablets, and other handheld devices. In practice, the A78 is typically deployed as the “big” core in a big.LITTLE arrangement alongside more energy-efficient cores to deliver strong performance when needed while preserving battery life for everyday tasks. For context, Arm licenses the Cortex-A78 to multiple semiconductor manufacturers, who then integrate it into their own system-on-a-chip products Arm and Armv8-A.
The A78’s development reflects ongoing industry emphasis on performance-per-watt and sustained performance under varied workloads. It builds on the Armv8-A instruction set architecture and adopts architectural improvements intended to raise Instructions Per Clock (IPC) while keeping power demands manageable. In many designs, the Cortex-A78 is paired with efficiency cores in a heterogenous multi-core layout, enabling devices to ramp up performance for demanding apps and keep power usage in check during lighter tasks big.LITTLE.
Design and architecture
Architecture and ISA: The Cortex-A78 is built on the Armv8-A family, using the 64-bit instruction set and providing modern features expected in contemporary mobile CPUs. This places the core in the same ecosystem as other Arm cores that dominate the smartphone and tablet markets, allowing a broad base of software and tooling support Armv8-A.
Core design and performance: ARM emphasized improvements in IPC, branch prediction, and memory subsystem efficiency relative to its predecessor. The A78 is designed to deliver higher sustained performance and better efficiency, particularly in thermally constrained mobile environments. In practice, many SoCs that deploy the A78 rely on a clustering of cores (often with one or more Cortex-A78 cores acting as the primary high-performance units) to deliver strong responsiveness in apps, games, and multi-tasking.
Cache and memory: The Cortex-A78 features a cache hierarchy intended to reduce latency and improve throughput for common mobile workloads. The exact cache sizes vary by product and vendor integration, but the goal is to keep data and instructions readily accessible for the CPU while coordinating with the wider memory subsystem of the system-on-a-chip.
Manufacturing and process nodes: The A78 has been fabricated on multiple leading process technologies, including 5nm-class nodes and 7nm-class nodes, depending on the partner foundry and design. The choice of node influences performance, power, and thermal characteristics of the final SoC that embeds the core. Foundries such as TSMC have played a key role in enabling these implementations for various customers TSMC.
Ecosystem and licensing: Arm licenses the Cortex-A78 to several semiconductor companies, which then build their own SoCs around the core. This licensing model supports a diverse ecosystem of devices and manufacturers, giving OEMs the ability to tailor performance and features to specific markets. The result is a broad, competitive landscape across major markets such as smartphones and other handheld electronics Arm.
Adoption and market impact
The Cortex-A78 quickly became a standard choice for high-end mobile devices in the early 2020s. In practice, it served as the performance workhorse in many SoCs produced by several major vendors:
Qualcomm: The Cortex-A78 formed the basis for the performance cores in several Qualcomm designs, notably the Kryo 680 core that appeared in the Snapdragon 888 family. This helped deliver flagship-class performance and responsive power efficiency across a wide range of Android devices Qualcomm Kryo 680.
Samsung: The Cortex-A78 also appeared in Samsung’s Exynos line, including high-end Exynos configurations used in flagship phones and other devices. This contributed to competitive performance in markets where Samsung ships its own SoCs alongside other manufacturers’ models Exynos.
Market implications: The availability of the Cortex-A78 through a broad licensing model contributed to a competitive ecosystem in which multiple OEMs could deliver devices that balance raw speed with battery life. Consumers benefited from devices that could run demanding apps, games, and multitasking while maintaining reasonable power consumption in everyday use.
From a right-of-center perspective on technology and markets, the A78-era ecosystem illustrates how standardized, widely licensed IP can spur competition among hardware manufacturers, encourage scale economies, and drive consumer value through better performance and longer battery life without requiring prohibitive entry costs for new players. The broad adoption across diverse manufacturers also reinforces global supply-chain resilience by avoiding dependence on a single vendor or a single design pathway, while still offering room for differentiation at the system level Arm Armv8-A.
Competition, policy, and debates
Open ecosystems vs. specialization: Proponents argue that a robust, license-based IP ecosystem (as exemplified by the Cortex-A78) supports competition among OEMs while maintaining a stable software and tooling base. The result is rapid innovation at the device level, with multiple firms competing on performance, efficiency, camera and AI integration, and thermal design, rather than competing solely on core architecture. Critics occasionally raise concerns about dependency on a single architectural family; however, the practical outcome has been a large, diverse marketplace with strong software compatibility and efficient production pipelines.
National security and supply chain resilience: A common debate around mobile CPU cores centers on supply chain risk and geopolitical considerations. Advocates for maintaining a broad, competitive ecosystem point to the ability of several foundries and design houses to produce Cortex-A78-based cores, spreading risk across suppliers and regions. This stands in contrast to scenarios where a few players control a narrow slice of the stack, which could raise costs, slow innovation, or create bottlenecks in times of tension or disruption. The Cortex-A78 ecosystem illustrates how modular IP licensing can enhance resilience while preserving consumer choice.
Open architectures and alternatives: Some observers advocate for broader adoption of open, royalty-free designs such as RISC-V as a hedge against licensing constraints and to spur even more diverse hardware ecosystems. From a pragmatic, market-oriented view, the Cortex-A78 represents a mature, well-supported option with an extensive tooling and software base that currently underpins billions of devices. Advocates for open architectures argue that competition would intensify with more open alternatives, while supporters of established ecosystems emphasize risk management, software maturity, and the economies of scale that come with decades of experience in the Arm ecosystem.
Security and performance trade-offs: As with any modern CPU design, security considerations—such as mitigations for speculative execution vulnerabilities and hardware-enforced isolation features—are part of ongoing development. The Cortex-A78-era products typically implement robust security features (e.g., TrustZone and memory protection mechanisms) in collaboration with their system software. Critics of market-driven approaches sometimes argue for stronger public sector involvement in security standards; proponents counter that the industry’s rapid iteration and real-world testing deliver more resilient outcomes for consumers.
Security and privacy
Modern Cortex-A series designs incorporate hardware protections intended to reduce the risk of exploit classes that affect many contemporary CPUs. In practice, devices built around Cortex-A78 cores rely on a combination of hardware features (such as isolation zones and memory protection units) and software-level mitigations to address vulnerabilities and safeguard user data. The emergence of hardware-assisted security features in mobile SoCs, alongside ongoing OS-level safeguards, reflects a broader industry emphasis on privacy and protection as devices become more central to daily life. In parallel, researchers and vendors continue to monitor and address side-channel risks, with firmware and microcode updates playing a role in maintaining resilience over time. The ecosystem’s breadth—with multiple vendors and devices—helps ensure that security lessons learned in one product can be ported across others, contributing to overall improvement in the space TrustZone Spectre (security vulnerability) Meltdown (security vulnerability).