Ars Technica puts iPhone 6s units through their paces to test battery life differences between Samsung, TSMC models

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Date: Tuesday, October 13th, 2015, 08:29
Category: battery, Hardware, iPhone, News, Processors, Software


In the wake of the controversy surrounding the iPhone 6s and 6s Plus’ battery life and how this might change depending on whether the battery was sourced from Samsung or TSMC, some research has been done that has discovered the battery life difference in “real-world usage” to be about 2 to 3 percent.

The cool cats at Ars Technica ran two iPhone 6s models, one with a Samsung chip and one with a TSMC chip, through their paces, to find the following results:

The devices were locked to AT&T with the SIM cards removed. The screen brightness in each handset was set to exactly 200 nits using a Spyder4Elite colorimeter, and the screen was left on at this brightness for the duration of all of our tests.

For the tests themselves, the battery life test that started this story off is the one included in Geekbench 3, which according to Primate Labs’ John Poole does include some idle time but is generally very CPU intensive. According to the Xcode Activity Monitor instrument, the Geekbench 3 battery life test generally keeps the CPU pegged between 55 and 60 percent load for the entire time it runs, with occasional dips below 55 percent and peaks above 60 percent.

Are Technica’s WebGL battery life test similarly kept the CPU (and the GPU) working continuously, but at a slightly lower level of load. CPU load for this test typically hovers between 45 and 50 percent, and the GPU Driver instrument says the GPU utilization is between 25 and 30 percent. The site ran the GFXBench GL 3.1 battery life test for good measure, which loops the “T-Rex” test 30 times while measuring performance and power drain. These two tests approximate the load that a 3D game might put on the A9.

Finally, most smartphone usage leaves the CPU and GPU idle for extended periods of time, which is where the Web browsing test comes in. It continuously loops some pages cached on one of our servers, loading one page every 15 seconds until the phone dies.

Each test was run at least twice to reduce the likelihood of outliers, and the results from both runs were averaged out to reach the numbers you see below (the Geekbench test was run three times).

The big takeaway was that the Samsung phone did have consistently lower battery life results than the TSMC phone. The one exception was the WebGL test, in which the Samsung phone barely edged out the TSMC phone.

Second, even though that’s true, the Geekbench test was the only test that caused what could be believed to be a significant difference, one that can definitely be attributed to the SoC rather than the screen or the battery itself or some other system component. All three of the other tests showed the two phones scoring within two to three percent of each other, which just happens to be the same figure Apple quoted to the press last week. The heavier Geekbench test, on the other hand, showed the TSMC phone lasting an average of 28 percent longer than the Samsung phone.

So there are definitely circumstances under which the TSMC phone will last longer than the Samsung phone, but it’s not a universal problem. A Samsung chip that’s mostly idling or even one under modest CPU and GPU load, though, is going to behave in just about the same way as a TSMC chip. And the kinds of CPU-intensive work that the Samsung chip seems to struggle with just aren’t that common on smartphones. Most of the time, iPhone 6S battery life should be similar no matter which chip your phone is using.

Be sure to check the link for full charts of the tests.

Stay tuned for additional details as they become available.

Via Ars Technica

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