Since we
first learned that the A9 SoC in Apple’s iPhone 6s lineup is dual sourced - that is that it's being made by two different vendors with two distinct manufacturing processes - one major question has remained in the process of reviewing these two phones. The main issue under question here is whether the TSMC A9 or Samsung A9 have any difference in performance and power consumption. If there is a difference, the question then becomes whether the difference is significant.
In an atypical move for the normally tight lipped manufacturer, Apple issued a statement this afternoon in response to these questions and some
rudamentary end-user benchmarking showing that there may be a difference:
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.
It interesting to see this response as Apple normally doesn’t comment on anything like this, which in turn is likely a good indicator of how seriously Apple is taking any concerns. However, this statement is also of interest because it's revealing in terms of what internal data Apple has collected on the issue. Apple has in recent years been one of the better companies in accurately promoting the battery life of their products, and that kind of accuracy comes not only from taking a conservative (safe) stance in marketing, but also collecting massive amounts of data to understand their products and their capabilities.
The Test
To get to the meat of matters then, let's talk about battery life, tests, chips, and statistics. In terms of the testing that has seemingly...
...
...where do we stand? The short answer is that all we know is that we don't know. What we know is that there isn't enough information currently out there to accurately determine whether the TSMC or Samsung A9 SoC has better power consumption, and more importantly just how large any difference might be. 1-on-1 comparisons under
controlled conditions can provide us with
some insight in to how the TSMC and Samsung A9s compare, but due to the natural variation in chip quality, it's possible to end up testing two atypical phones and never know it.
To that end I suspect that Apple's statement is not all that far off. They are of course one of the few parties able to actually analyze a large number of phones, and perhaps more to the point, having a wide variation in battery life on phones - even if every phone meets the minimum specifications - is not a great thing for Apple. It can cause buyers to start hunting down phones with "golden" A9s, and make other buyers feel like they've been swindled by not receiving an A9 with as low the power consumption as someone else. To be clear there will always be some variance and this is normal and expected, but if Apple has done their homework they should have it well understood and reasonably narrow. The big risk to Apple is that dual sourcing A9s in this fashion makes that task all the harder, which is one of the reasons why SoCs are rarely dual sourced.
As for AnandTech, we'll continue digging into the matter. Unfortunately all of the iPhones we've received and purchased so far have used TSMC A9s - it's a silicon lottery, after all - but whether there is a real and consistent difference between the TSMC and Samsung A9s is a very interesting question and one we're still looking to ultimately be able to address.
