(iTers News) – Rumors have it that Samsung won’t embed a much-hyped Exynos 5 octa-core CPU in a new generation of Galaxy 4 smart phones, because the first commercial roll-out of ARM big.Little processor architecture generates too much heats, guzzling more power than expected.
Instead, Samsung will incorporate Qualcomm Snapdragon 600 to power the Galaxy S4 smart phone until it will mend the overheating problem, an industry analyst familiar with the Exynos octa-core CPU.
The Exynos 5 octa-core CPU is the first commercial implementation of ARM big.Little architecture that incorporates two ARM quad-core processors-a low-power ARM Cortex-A7 and a high-performance ARM Cortex-A15 in a single silicon die.
The big.Little architecture was meant to balance performance envelop and power budget, letting high-performance A15 processor to perform duty-heavy computing jobs like graphics rendering and full HD 3D video playback, while assigning energy-efficient A7 to mainly work out light workloads.
The idea is to optimize performance and power consumption depending on workloads. In theory, , for example, the balancing act will result in up to 70% power and energy savings, compared with when high-voltage and high-performance A15 works alone, often overworking light processing workloads and thus wasting power.
Yet, the reality is going the opposite way. .
What are mainly blamed for the overheating are so-called bus contention and the static power consumption.
The Exynos octa-core CPU has one dedicated bus interface to boot up data from on-chip memory, but each core is contending with each other to get faster access to data on-chip cache memory, often resulting in data latency.
The power consumption of a CPU is a total sum of static, or leakage power and dynamic power consumption.
On the 8-core layout of Exynos 5 octa-core CPU, some cores are operating at or near a peak frequency, mainly consuming dynamic power, while other cores sit idle, or in a standby mode, but still co