Damir Franc, regular YouTuber, has recorded and published a ten minute report detailing his experiences of the HTC One M9 powered by the Qualcomm Snapdragon 810, comparing it with the Sony Xperia Z3 (powered by the Snapdragon 801) and the Samsung Galaxy S6 (powered by the Samsung Exynos 7420). Damir makes a number of observations regarding the Snapdragon 810's performance, heat and battery life in the HTC One M9 in his ten minute video clip, many of which are mirrored by the Android Headlines team's experience of the device. The report follows a difficult six months for Qualcomm with stories running across the Internet regarding the Snapdragon 810's reputation for overheating, throttling, shutting down the higher powered ARM Cortex-A57 cores and chewing through an inordinate amount of battery.
Damir's comparison is between quite different devices, built from different material and of course using different flavors of Android as the Sony Z3 runs Sony's modified Android and the HTC uses the Sense overlay on top of Android 5.0 Lollipop. Damir's first observation, however, is that the Qualcomm Snapdragon 810 shows some throttling when being benchmarked. Most benchmarks are unrealistic comparisons of devices because they do not reflect real world use of the device: a typical benchmark will run all processor cores at the maximum speed. Some custom software overlays will detect when a benchmark is being run and deliberately activate a high power mode for the processor, which may include keeping all cores active at the highest frequency and even extending throttling temperature limits so as to obtain the highest possible benchmark score. Damir's tests showed that the HTC One M9 throttled the result such that it performed broadly in line with the Sony Xperia Z3 device after three or four test runs, but that the initial tests were quicker. However, away from benchmarks the M9 is fast and smooth running applications and games even after many minutes of play time.
The other side of the performance of the Qualcomm Snapdragon 810 is that of heat, and here Damir notes that the HTC One M9 runs warm. The device heats up quickly when used even if just for a few minutes, which is partially thanks to the aluminum chassis and case design and partially because the Snapdragon 810 produces a lot of heat. Damir explained that not only does the device run warm in the hand but feels uncomfortably warm when placed in the pocket. It also takes some time to cool down as well; he notes that the Sony Xperia Z3 and Samsung Galaxy S6 also warm up (not so much) but cool down quicker. This could be a materials design choice by HTC; perhaps the battery acts as a heat soak for the motherboard and processor? Writing of the battery, Damir notes that the HTC One M9 shows less screen on time compared with the Z3, with around half of the screen on time. Here is where there is another difference between how the Sony and HTC perform as the devices have different screens and underlying technologies. Damir did not comment on how well the HTC One M9 performs in standby, which reflects partially the processor but also the modem and the rest of the device.
Damir's final observations follow his reflection on how well the HTC One M9 performs: yes, it's quick and smooth, but so too are the previous generation Snapdragon processors, the 801 and 805 (and although slightly less so, the Snapdragon 800 too). For a user thinking of upgrading to a device powered by the Snapdragon 810 but currently using a Snapdragon 801 or 805 device, the transition is not worth it. The heat issue is easily explained: each of those ARM Cortex-A57 cores is capable of chewing through 4 watts of power (and producing this much heat), whereas the M9's chassis is unable to dissipate this much heat. In a larger chassis with improved cooling, the Snapdragon 810 may not throttle so much, but even when throttling the System-on-Chip performs very much in line with previous generation chipsets. This reflects the industry's current challenge: we have reached the point whereby our SoCs are able to produce significantly more heat than our chassis designs can remove. We need to produce less heat or improve cooling. Devices such as the OnePlus Two aim to improve cooling with graphite layers embedded in the device, plus Qualcomm's next-generation SoC, the Snapdragon 820, will be built on a smaller manufacturing process, which should reduce the heat produced in use.