It turns out it doesn’t matter: ARM says that while the two types of chips were originally designed to offer different performance levels, but due to demand for better performance and efficiency, ARM Cortex-A12 and Cortex-A17 are effectively identical.
In fact, ARM doesn’t even plan to use the Cortex-A12 name anymore and will refer to all of the designs in this category as Cortex-A17.
Cortex-A17 chips offer 60 percent more single-threader performance than a Cortex-A9 chip at the same clock speed, while also offering better efficiency.
These are still mid-range chips that aren’t in the same class as the Cortex-A57 designs based on ARMv8 architecture. But if you’ve been spending the last year wondering whether Rockchip’s latest processor was a Cortex-A12 or Cortex-A17 chip now you can move on to other pursuits.