If you’ve purchased a new phone the past few years, chances are good that it is powered by one of Qualcomm’s SoC’s. The company has smartly used a combination of custom CPU/GPU architecture and advanced LTE modems to increase it’s market share over its competitors (even putting them out of business)
Despite the long continuous success of their flagships, the 810 has been a disappointment. Best case, it is faster than the 805 and the other chips that it will be replacing. However, in recent flagship phones, they have been found to run hot and as a consequence thermal throttling has crippled long term performance.
While thermal throttling is normal in small devices such us smartphones, tablets and laptops (to avoid melting down the core) the 810 runs unusually hot. Its direct competitor, the Exynos 7420 – which runs a similar build of cortex a53 and a57 and running at roughly the same max clock speed still manages to outperform it at extended use scenarios.
Long story short, all modern SoC throttle, but the 810 is the worst offender. It’s so severe that the chip actually runs slower than older SoCs in extended runs. The Exynos 7 Octa- which has the same or similar specs is a much better chip in real world scenarios.