Intel 8th Gen Core Mobile Performance Review: Kaby Lake R Explored

Intel Kaby Lake R: Battery Life And Conclusion

Performance gains are great, but arguably the most important metric for an ultrabook is battery life. Consumers opt for these thin and light devices when they need to get work done on the go and without being tied down to a power outlet. More cores are nice, though generally not worth sacrificing hours of charge, at least for most mainstream users.

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. In all tests, Windows 10 Quiet Hours have been enabled and the 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. 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.

Our custom HotHardware video loop test takes a 1080p HD video with a 16Kbps bit rate and loops it repeatedly, with 1 minute break intervals in between. A timer log file increments minutes of uptime every minute and a final minutes total recorded before system shutdown is stored in the log. This is a lighter duty test that is still a bit more strenuous than say many office productivity tasks but it's not nearly the strain that Battery Eater puts on a system.

acer swift 3 bench hh video loop v2

Battery Eater Pro wears systems down quickly with a heavy load on all subsystems, including processor, graphics, memory and even storage. This is truly a worst-case test that will give you a sense of how a machine will hold up under heavy strain, when gaming or under heavy-duty continuous content creation workloads, for example.

acer swift 3 bench battery eater v2

Our battery benchmarks tell an interesting tale. The Kaby Lake Refresh notebooks lose out to their predecessor in the lighter-load video loop test by 20-30 minutes. Conversely, when being pushed to the max in the Battery Eater benchmark, the Kaby Lake R chip emerges on top by a hair. We still need to consider the newer model's 2.5 WHr greater battery capacity, but it appears battery life is at least comparable to previous generation chips which is all we can ask for. We will note that Dell recently refreshed XPS 13 with Kaby Lake R actually shows improved battery life relative to their predecessors, though those were not tested side by side so software optimization or other factors could also be responsible there. Another final note is that the 14-inch display of the Acer Swift 3 series isn't very bright and we had to push them harder than most to get respectable brightness levels for testing. This significantly affects battery life negatively. We'd offer that Dell's XPS 13 is a better reference point to measure against for ultrabook battery life with a 1080p display and Intel 8th Gen processors.

Intel 8th Gen Core Series Final Thoughts

Intel has hit it out of the ballpark with the Kaby Lake Refresh. In fact, calling it a "refresh" really sells it short. This is the most dramatic single generation performance gain we've seen for thin and light notebooks in some time and with virtually no trade-off required for battery life. In fact, in some light duty use cases, due to 8th Gen Core's lower base clocks, battery life should be extended a bit as well. 
8th Gen Intel Core Series Processor
There does not appear to be any drawback to these chips, compared to seventh generation Kaby Lake, with the exception of potentially higher power draw on heavier workloads. In exchange, we see modestly improved single-threaded performance (10-15%) due to higher boost clocks, dramatically improved multithreaded performance (up to about 75%) thanks to doubling the core count, and even an uptick in integrated graphics performance (up to 35%) due to a less CPU-bound architecture.

acer swift 3 8gen keyboard

For their part, the Acer Swift 3 notebooks are impressive machines for the price, even if we are not reviewing them outright. In relation to more premium laptops, they can compete toe to toe with performance, provide a healthy I/O selection, and have solid build quality. Some users may prefer a notebook with a smaller form-factor, higher resolution screen, touch display, or greater battery life, but we feel students, professionals, and even light gamers can all find something to appreciate with the latest generation of the Acer Swift 3 14-inch.

acer swift 3 7gen v 8gen

I think it's time to trade up my own Broadwell-era XPS 13 now - these Kaby Lake R models are definitely HOT.

  • Quad-core with HyperThreading
  • 10-15% faster single threaded
  • Up to 75% faster multi threaded
  • Better overall graphics performance
  • Slight battery life impact depending on workload

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