Samsung unveiled Exynos 5 Octa earlier this year. The processor is based on ARM's big.LITTLE micro-architecture and packs eight cores. One of the two sets of cores consists of high-performance Cortex-A15 cores while the other set of cores is energy-efficient Cortex-A7. When revealed, Samsung did not specify power consumption and now it seems for a reason.
According to DigiTimes, Samsung is struggling with Exynos 5 Octa processor in terms of power consumption and temperature. This should make Samsung use a competitor's solution in next-gen flagship smartphone. Though, this might not be a bad thing as Snapdragon 600 is a beast chip plus it covers most of the world's networks.
This theory does confirm previous rumours. The 600 employs the Adreno 320 GPU we've seen in leaked benchmarks while CPU's clock speed fits with reports. Will Samsung use Qualcomm's solution or they will stick with Exynos remains to be seen.