Do 8 Cores Really Matter in Smartphones?

As the smartphone industry has begun to mature, one-upmanship among smartphone manufacturers and SoC vendors has bred a dangerous trend: ever-increasing processor core counts and the association between increased CPU core count and greater performance. This association originated as SoC vendors and OEMs have tried to find ways to differentiate themselves from one another through core counts. Some vendors are creating confusion, as phones today have core counts from 2 up to 8 and vary wildly in performance and, even more importantly, experience. One reason for this confusion is many users and reviewers have used inappropriate benchmarks to illustrate smartphone user experience and real world performance. As a result, we believe that some consumers are misled in their buying decisions and may end up with the wrong device and the wrong experience.

The 8 Core Myth…
The 8 Core Myth, also known as the Octacore Myth, is the perception that more CPU cores are better and having more cores means higher performance. Today’s smartphones range from 2 cores up to 8 cores, even though performance and user experience are not a function of CPU core count. The myth, however, will not be limited to 8 cores, as there are plans for SoCs with up to 10 cores, and we could even see more in the future.

Not All Cores Are the Same…
In some phones, users are getting Octacore designs with up to 8 ARM Cortex-A53 cores. These 8 cores perform differently than 4 ARM Cortex-A57 cores paired with 4 ARM Cortex-A53 cores in what is called a big.LITTLE configuration. Core designs vary wildly from ARM’s own A53 and A57 64-bit CPUs to Intel’s x86 Atom 4-core processors to Apple’s 2-core A8 ARM processor. All these processors are designed differently and behave differently across application workloads and operating systems. Some cores are specifically designed for high performance, some for low power. Others are designed to balance the two through dynamic clocking and higher IPC (instructions per clock). As a result, no two SoCs necessarily perform the same when you take clock speed and core count into account.

Through the different benchmarks, tools, and applications, we showed that CPU core count in a modern smartphone is not an accurate measurement of performance or experience. More CPU cores are not always better. We do acknowledge that having many smaller cores is one way to simplify power management, but these tests are not focused on power; they are focused on performance and user experience.

CPU core counts are not the way that phone manufacturers or carriers should be promoting their devices. CPU core count is only one factor in Android when the SoC has fewer than 4 cores. The marketing of core counts as a primary driver of performance and experience must end and be replaced with improved benchmarking practices and education.

Hopefully this will be the start of a meaningful discussion in the comment section…

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