As we reported last week, the Taiwanese company is sampling a new quad-core SoC using ARM big.LITTLE architecture for the tablet market. The difference in this new quad-core SoC solution is that MediaTek is adding HMP capability to the SoC.
The Samsung Exynos 5 Octa is another SoC using the big.LITTLE architecture, but MediaTek and Samsung have implemented it differently. The Exynos 5 Octa uses what Samsung calls cluster migration -- the same technique others have used with big.LITTLE implementations. The CPU migration mode moves jobs between clusters of cores. When a high-performance operating point exceeds the capabilities of the quad A7s, the scheduler shuts them down and moves everything to the A15s.
MediaTek is adopting the HMP approach, which it says can assign individual threads to the best core, thus promising better results.
"In Samsung's case, either the big or the LITTLE cores are running, but not simultaneously," Mark Hung, wireless research vice president at Gartner, told us. In MediaTek's case, one, two, three, or all four cores may be running.
Mike Demler, senior analyst at the Linley Group, gave us this explanation for our post last week:
With MediaTek's HMP, the operating system still sees a quad-core CPU, but it can assign (or shift) a task to any CPU independently. The A15s can run at the same time as the A7s. Tasks can still be moved from one to the other for power-performance optimization.
HMP in an octa-core processor?
Just to be clear, MediaTek's newly announced tablet SoC is a quad-core device. However, the company has also joined the eight-core processor bandwagon. A spokesperson recently confirmed speculation about MediaTek's plan to launch an octa-core solution in the fourth quarter.
MediaTek is distinguishing itself from competitors (such as Samsung) by calling its solution "True Octa-Core" processing. What's so true about it? In MediaTek's opinion, it's the addition of HMP to its Octa-core solutions.
The company says on its website, "MediaTek True Octa-Core intelligently allocates processing power to where it is needed, both on a per-application and per-task basis." A white paper to be released soon (and recently obtained by EE Times) explains the process further:
This architecture reveals a significant departure from the load handling systems of other multi-core solutions – even those with eight cores -- which typically tend to restrict tasks that are too demanding, resulting in poor response times or shutdowns.
It remains to be seen whether HMP will be a defining factor in the multi-core mobile apps processor race. But by becoming the first to adopt HMP, MediaTek is banking on that premise.