Samsung is finally using the big.LITTLE MP architecture in its eight-core chip.
Samsung has certainly caught some grief over the way it has marketed the Exynos 5 Octa chip (5410) for smartphones and tablets since its introduction back in Q2 2013. The company placed a heavy promotional emphasis on the chip's eight cores as a source of superior performance and speed. And while yes, the chip does have eight physical cores, ARM's big.LITTLE architecture prevents all eight from firing up at once. The SoC either uses the Cortex-A7 cores or the Cortex-A15 cores, depending on the application.
Then in July 2013 the company began teasing an "evolved" Exynos 5 Octa chip, firing up speculation that this version might actually switch on all eight cores simultaneously by using ARM's new and improved big.LITTLE MP (multi-processing). That wasn't the case at all. Instead, Samsung replaced the GPU cores and cranked up the clock speed of the CPU cores just a notch in the "extreme" follow-up chip (5420). Thus the company's eight-core chip still performs like a quad-core model, but provides better overall performance than the original.
Now Samsung has plans to introduce what seems to be a software update based on big.LITTLE MP, aka Heterogeneous Multi-Processing (HMP), enabling the use of all physical cores at the same time. HMP will send software threads with high priority or high computational intensity to the 'big' Cortex-A15 cores while threads with less priority or are less computationally intensive can be performed by the 'LITTLE' Cortex-A7 cores.
"Software implementation is essential to maximizing the benefits of big.LITTLE technology," the company said. "Multi-processing software controls the scheduling of threads of execution to the appropriate core. In earlier versions of the big.LITTLE software, the whole processor context is moved up to the 'big' core or down to the 'LITTLE' core based on the measured work load. In-depth study and analysis of diverse use case scenarios enable Samsung to achieve efficiency and high-performance, while managing power levels to deliver optimal user environments."
The latest "evolved" Exynos 5 Octa chip contains six ARM Mali-T628 GPU cores, four Cortex-A15 cores clocked at 1.8 GHz and four Cortex-A7 cores clocked at 1.3 GHz. The new chip also has a memory bandwidth of 14.9 GB/s paired with a dual-channel LPDDR3 at 933 MHz, and a variety of Full HD 60 frames per second video hardware codec engines. The chip is even capable of performing General-Purpose computing on Graphics Processing Units (GPGPU), and supports OpenGL ES 3.0 and Full Profile Open CL 1.1. This new chip is in the Samsung Galaxy Note 3 and the Galaxy Note 10.1 2014 Edition.
"ARM big.LITTLE multi-processing technology delivers the highest performance and efficiency across the widest range of workloads," said Noel Hurley, vice president, Strategy and Marketing, Processor Division, ARM. "We welcome Samsung's continued commitment to deploying the leading-edge technology on their latest chips featuring the ARM Cortex-A series of processors, ARM Mali GPUs and ARM Artisan physical IP."
Samsung said the HMP solution for Samsung's Exynos 5 Octa SoCs will be available to customers in 4Q of 2013.