HP Zbook 14u G6 Review: A Thin, Powerful Mobile Workstation
HP Zbook 14u G6: Battery Life, Acoustics, and Thermals
Since laptop 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 laptop displays vary in brightness at each respective 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 - How We Test
Our custom HotHardware video loop test takes a 1080p HD video with a 10Mbps bit rate and loops it repeatedly, with 1-minute break intervals in between playbacks. A timer log file increments minutes of up-time every minute—along with the grand total—before system shutdown is stored in the log.
Overall battery life on the Zbook 14u G6 was pretty darn good in our video playback test, where HP's mobile workstation lasted six and a half hours. That was good enough to edge out several other notebooks with 4K displays like the Lenovo ThinkPad X1 Carbon. While the Radeon Pro drivers are set to have the integrated graphics processor handle VLC playback, HWMonitor says that the discrete GPU consumes around 5 watts even on battery power. Still, we can't help but notice that the Zbook fell short by 17 minutes compared to the XPS 15 with an eight-core CPU and a much faster consumer GPU, even though both systems had roughly the same battery capacity. Perhaps the Dell machine's OLED panel was more energy-efficient than this machine's IPS display.
HP Zbook 14u G6 Acoustics and thermals
To test sustained thermal performance, we fired up 3D Mark and ran the benchmark in a window while observing CPU temperatures with HWMonitor and GPU temperatures with GPU-Z. This allowed us to make sure that we had a big thermal load on the whole system—not just the CPU—and make sure that the cooling system could handle the load without heavily throttling the processor or GPU. After all, the CPU is power limited to make room for the Radeon Pro GPU, so hopefully power consumption is low enough to let the cooling system do its job.
There were absolutely no surprises here. The Zbook runs its CPU in the default 15W configuration, which results in all-core turbo boosts that settle in at 2.2 GHz. Never did it ever dip below that, but when a lightly-threaded test allowed for it, the CPU cores were actually allowed to spin up quite a bit faster to up over 3 GHz. That's really great when the GPU is running all-out trying to render the scene smoothly. Temperatures walked right up to 98 Celsius. The GPU couldn't maintain its initial 1,080 MHz, but it still stayed close to 950 MHz throughout. That's an acceptable trade-off, considering the fact that a discrete GPU does generate quite a bit of heat on its own for such a small notebook. Since the performance never took a nosedive, we're confident in saying that the Zbook's cooling system is up to the task of keeping both the processor and discrete graphics processor running within their thermal constraints without significant throttling. The machine does get rather warm to the touch, but since it's aluminum, this just helps the machine dissipate additional heat. The Zbook's hot zone was concentrated to the area above the keyboard on the left side where the heat pipes lead towards the vent.
Even better, the system didn't get overly loud while maintaining that temperature. To measure sound pollution, we used our Galaxy S10+ and a sound measuring app which had our room at right around 29 dB. Six inches from the side of the system, our phone could only pick up around 36 dB of noise, while it was barely audible from the front of the mobile workstation—just 34 dB. The sound of fan was overall a woosh of air with no hint of whine or resonant hum, and according to HWMonitor, the fan never got faster than 70%. There was also no hint of coil whine, either, which is exactly what we expect from a machine of this caliber and price. Overall we're pleased with thermal performance and noise produced by the system. If you require lower temperatures, you can always crank the fan up to the maximum with a utility.
