NVIDIA revealed that Kal-El, the third-generation Tegra chip, will feature a fifth core to enhance energy efficiency. Just like the four regular cores the fifth core is an ARM Cortex A9-based companion core, but it's manufactured on a low-power process and intended to run up to 500MHz only. According to NVIDIA, the companion core enables power savings of 14 to 61 percent compared to Tegra 2. Full details about the fifth core and more new features of Kal-El can be found in these two whitepapers on NVIDIA's blog.
The first whitepaper outlines the patented fifth core. This extra core – which we call the “companion core” – runs at a lower frequency and operates at exceptionally low power.
During less power-hungry tasks like web reading, music playback and video playback, Kal-El completely powers down its four performance-tuned cores and instead uses its fifth companion core. For higher performance tasks, Kal-El disables its companion core and turns on its four performance cores, one at a time, as the work load increases.
The Variable SMP architecture is also completely OS transparent, which means that operating systems and applications don’t need to be redesigned to take advantage of the fifth core.
The second whitepaper discusses the benefits of quad-core across different types of use cases – web, games, apps, multitasking and more. We also highlight examples of how quad-core Kal-El uses less power than dual-core processors across all performance points.
Project Kal-El also includes a brand-new 12-core GPU that delivers up to 3x the graphics performance of Tegra 2, as well as several additional new capabilities. We’ll have more details on these aspects soon.