Asus ZenBook 3 Review: An Intel Kaby Lake-Powered Ultrabook

In the following benchmarks we employ two very different battery life tests--Battery Eater Pro and a custom 1080p HD video loop test--to prove out battery life with our test group of machines and the ASUS ZenBook 3. In all tests, Windows 10 Quiet Hours have been enabled and displays are calibrated with lux meters on pure white screens to as close to 115 lux as possible. For the average notebook this is somewhere between a 45 - 60% brightness setting, but it will vary from system to system. 

Since notebook displays significantly affect power consumption and battery life, it's important to ensure a level playing field with respect to brightness of the display for battery testing. However, since many notebook displays vary in brightness at each respective brightness setting in Windows, this calibration with the meter is critical to ensure all displays are set to as near identical brightness as possible before testing.

Battery Life Testing Heavy-Duty Workload And Light-Duty Battery Life Performance Tests

Battery Eater Pro provides a heavy load on the laptop and generally runs through its battery life much faster than our custom video loop test. Our video benchmark helps you get a sense of how long the laptop will handle ordinary tasks while on battery power; Battery Eater Pro presents a worst-case scenario. 


The ZenBook 3 offered very good battery life, despite its relatively small size. The 40Wh lithium polymer battery in the machine held out for over 2.5 hours in BEP, and the machine finished near the top of the charts. In the more forgiving video loop test, the ZenBook 3's battery lasted for more than 5.5 hours.  ASUS claims roughly 9 hours of battery life with the ZenBook 3, which is entirely possible with typical use -- even longer battery times are possible with lighter use. 

Acoustics And Temperatures: When tooling around the desktop and running light-duty office-type applications, the ASUS ZenBook 3 is mostly silent. With less demanding workloads, its cooling fan will spin up slightly, but the machine is not loud by any means. Under a sustained, heavy workload, however, the cooling fan will spin up to a much more audible level. We wouldn't consider it loud in comparison to other Ultrabooks, but the fan can definitely be heard when running full bore.  You can get a taste for the ZenBook 3's fan noise towards the end of the video embedded on the first page.

With such a small chassis and cooling system, the ZenBook 3 -- like any similarly sized machine with equivalent performance -- will have some thermal constraints. The system's skins do not get terribly hot. As you can see in the maps above, the warmest external surfaces after hours of benchmarking just barely broke 100°F. The ZenBook 3 does, however, exhibit some throttling when under sustained workloads.  This behavior likely won't be an issue for day-to-day, bursty computing tasks, but we wanted to illustrate what could happen if you're hammering on the machine non-stop, nonetheless.


The generate the data above, we ran the Cinebench R15 multi-threaded CPU benchmark repeatedly. In runs 1 through 7 we restarted the test and quickly as possible, as soon as the previous run finished. Then in run 8, we waited 30 seconds for the machine to cool down a bit before kicking off the test. And for run 9, we waited a few minutes to allow the machine to cool thoroughly and reach an idle state.

Ideally, logging temperatures, clocks, and scores over time would paint a completely picture, but that's a mountain a data to pour through. What you see above is the average CPU temperature at the start of the test run, the max CPU temperature during the run, and the final Cinebench score. As the machine heats up, and its cooling solution gets more thermally saturated, the CPU must throttle back, which drags the score down a bit.  If you keep hammering on the system, the score remains low. But once it has had a chance to cool down, performance returns to higher levels.