Battery Life And Thermal Throttling
Battery life may be the most important performance metric for a mobile device. After all, it does not matter how quickly a phone or tablet can load webpages or how many frames per second the GPU can crank through once the battery runs down and the device shuts off. To learn more about how we test this critical facet of mobile computing, please read our battery testing methodology article.
The PCMark system test estimates battery life using real-world workloads and reflects how long a phone can last while continuously working on common tasks. Kirin 950's improved power efficiency, combined with the Mate 8's big 4000mAh battery, helps it last 9 hours and 23 minutes, the longest of any device we've tested, edging out Samsung's Galaxy S6 edge+ at 523 minutes and Motorola's Moto G (3rd gen) at 507 minutes. This feat is made even more impressive by the Mate 8's chart-topping performance score. Our colleagues at AnandTech examined Kirin 950's power efficiency in greater detail, which helps explain the Mate 8's outstanding results in PCMark.
The Mate 8 also does well in the GFXBench 3.0 battery test, which focuses on the GPU and is an indicator of battery life during intense gaming, lasting 3 hours and 45 minutes. We've seen a few devices last longer, but only because thermal throttling forced them to lower GPU frequency.
The Mate 8 exhibits good performance stability while gaming, staying within 94 percent of its peak performance over the first 30 minutes of T-Rex. After this we see the Mate 8 throttle back a bit, briefly reducing performance to 85 percent, but overall it's able to maintain near peak performance.
Looking at these results adds new context to HiSilicon's decision to use a quad-core GPU in the Kirin 950. By focusing on sustained performance rather than peak performance, a somewhat risky decision from a marketing standpoint, the Kirin 950 actually provides similar, if not better, performance after a few minutes of gameplay as compared to some other high-end SoCs, such as the Exynos 7420 or Snapdragon 810, at least when paired with a 1080p display like in the Mate 8.