http://www.wired.com/2015/10/iphone-6s-a9-battery-life/ So what’s the brouhaha all about, you ask? Well, Apple tapped two different partners to manufacture the A9 processor that is the brain of the iPhone 6S and 6S Plus. The horror! What’s more, those vendors used different manufacturing processes, resulting in an A9 from TSMC that is ever so slightly bigger than the A9 from Samsung. As you might expect, the Internet has gone absolutely bananas over this. A handful of anonymous forum members recently reported that iPhone 6S and 6S Plus handsets with Samsung inside have shown significantly worse battery life when running Geekbench, a popular processor benchmarking app. The fracas quickly moved beyond Apple forums and Reddit comments, spreading like a contagion from obscure tech blogs through the interwebs to esteemed generalist publications like The Guardian. The takeaway seems to be that there are “good” iPhones and “bad” iPhones. The Apple Statement “With the Apple-designed A9 chip in your iPhone 6s or iPhone 6s Plus, you are getting the most advanced smartphone chip in the world. Every chip we ship meets Apple’s highest standards for providing incredible performance and deliver great battery life, regardless of iPhone 6s capacity, color, or model. Certain manufactured lab tests which run the processors with a continuous heavy workload until the battery depletes are not representative of real-world usage, since they spend an unrealistic amount of time at the highest CPU performance state. It’s a misleading way to measure real-world battery life. Our testing and customer data show the actual battery life of the iPhone 6s and iPhone 6s Plus, even taking into account variable component differences, vary within just 2-3% of each other.” That first paragraph doesn’t help much, unless you’re on Apple’s marketing team. The second, though, says quite a bit. Apple is arguing that even if GeekBench shows a wide performance gap, that has little to no bearing on real-world usage. Apple is correct. GeekBench is plenty helpful, but it’s typically used to measure processor performance, not battery life (though the two are obviously associated). As such, it works by putting more sustained strain on the SoC than you would in an average day of web browsing, app refreshing, and Candy Crushing. That can make small differences in performance appear much larger when extrapolated out over an eight hour battery life. There’s an exception to this. People who game intensively for hours on end will push their CPUs harder than an average user, in which case those hypothetical differences may become noticeable. Even then, though, it doesn’t appear that anyone has actually shared an example of it happening in real life. It’s all just anonymized software estimates. And even if someone did show real-world variance, it’s impossible to know whether it’s that specific chip, or the fab it came from. We’re right back where we started. The only way to know what kind of real-world performance the iPhone puts out in the aggregate is to collect that data from a huge quantity of units, and the only company that’s done so is Apple (thanks to the “Diagnostics & Usage Data” it collects from those who opt in) and Apple’s on record that the differences are negligible. Frankly, there’s not much further to take this.