Arm Cortex-A78C targets laptops and hand-held console performance

A few days ago Arm quietly presented its Cortex-A78C CPU core in a blog post. The processor is based on the previously announced Cortex-A78, but has a higher performance target than smartphones. The Cortex-A78C is primarily designed for always-on laptops and other high-performance, battery-powered products. With arm-powered Macs just around the corner, the Cortex-A78C could end up as a competing CPU in the Windows on Arm ecosystem for 2021 laptops.

Android Authority sat down with Arm to learn a little more about the pros and cons of the CPU offshoot.

As can be seen from the name nomenclature, this chip is an adaptation of the Cortex-A78, with which future smartphone chipsets are to be operated. To close the performance gap between handsets and laptops, the A78C was developed for a larger number of cores. Up to eight CPU cores can now be present in a cluster, and four in the smartphone class Cortex-A78. This brings the design more in line with competing multi-core laptop processors.

To that end, Arm redesigned its DynamIQ Shared Unit (DSU) to support the larger silicon layout required by eight large CPU cores. The DSU also supports up to 8MB of L3 cache, allowing the cores to work together on large data sets stored in memory. This corresponds to the even more powerful Cortex-X1.

The Cortex-A78C core also differs slightly from the standard Cortex-A78. It implements instructions from recent revisions of the Armv8.X architecture, such as B. Armv8.3’s pointer authentication and other security-related functions. As a result, the CPU cannot be paired with existing Armv8.2 CPUs like the Cortex-A55 for a big.LITTLE arrangement. We’re looking at six or eight big-core configurations. This wouldn’t be well suited for mobile devices, but low core energy efficiency isn’t that important in the laptop market.

Otherwise, the performance and performance goals are exactly the same as the existing Cortex-A78. We expect an improvement of around 20% from a 7 nm Cortex-A77 to a 5 nm Cortex-A78. The C variant was developed to take into account some computational functions and to increase the multi-core performance.

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What is the Cortex-A78C for?

The Arm Cortex-A78C is intended for the connected PC, laptop, and possibly even Chromebook markets. Essentially, it’s an upgrade path for chipsets like the Qualcomm Snapdragon 8cx with even more power for desktop-class computing workloads. While we mustn’t forget that Arm’s CXC program partners also have access to the Cortex-X1, which promises bigger single-core gains. So we just have to see what Arm’s partners think of the options.

Arm also has its eye on the mobile game and handheld console market. Although it is known exactly which form factor and which products Arm’s partners have in mind. However, there is a very popular arm handheld console from Nintendo that is said to be updated in 2021. Nvidia’s Tegra X1, which drives the switch, is based on old Cortex-A57 and Cortex-A53 cores. An improved chip could certainly benefit from more modern and more powerful Cortex-A78C cores. But SoCs usually come before products. So let’s get stuck.

We’ll have to wait for chipset announcements from Arm’s partners to get a better look at possible products. The Cortex-A78C is already with Arm’s partners and announcements are expected throughout 2021.

Next: What Nvidia’s purchase of Arm means for your next smartphone