YouTuber Austin Evans put the iPhone 6s to the test and found that not all models are made the same.
Turns out, the 6s was has two types of processors inside their already fragile phone bodies. The first is a TSMC chip, and measures at 16 nanometers. The second is an Samsung chip, and measures in at 14 nanometers.
Well it turns out, models that contain the TSMC phone lasted a full 50 minutes longer than its Samsung brother. On top of this, the TSMC phone ran cooler as well.
Evans suggested that the curious should use the Lirum phone app, which will tell users what the model number of the phone is. If your phone has the model number N71AP, it contains a Samsung chip. If it has the model number N71MAP, it contains the TSMC chip. The app is free, so it's super easy to discover which phone you ended up with.
There's no way of knowing what model you're going to end up with before buying the phone, but at least you'll know what kind of hassle you're getting into. Hopefully Apple will issue a recall and switch out the phones for users who are unhappy.