20 December 2017

Geekbench: “iPhone Performance and Battery Age”

First, it appears the problem is widespread, and will only get worse as phones (and their batteries) continue to age. See, for example, the difference between the distribution of iPhone 6s scores between 10.2.1 and 11.2.0.

Second, the problem is due, in part, to a change in iOS. The difference between 10.2.0 and 10.2.1 is too abrupt to be just a function of battery condition. I believe (as do others) that Apple introduced a change to limit performance when battery condition decreases past a certain point.

If the performance drop is due to the “sudden shutdown” fix, users will experience reduced performance without notification. Users expect either full performance, or reduced performance with a notification that their phone is in low-power mode. This fix creates a third, unexpected state. While this state is created to mask a deficiency in battery power, users may believe that the slow down is due to CPU performance, instead of battery performance, which is triggering an Apple introduced CPU slow-down. This fix will also cause users to think, “my phone is slow so I should replace it” not, “my phone is slow so I should replace its battery”. This will likely feed into the “planned obsolescence” narrative.

John Poole

I’ve experienced the ‘sudden shutdown’ a couple of times in the last months on my iPhone 6, but I doubt the issue was fixed with a software update as Apple claims; I’ve had more shutdowns after updating than before. I’ve also noticed overall performance is getting worse for some time now, even while staying on iOS 10; apps would take full seconds to refresh and the screen sometimes fails to respond to touch as if the device is busy with some particularly complicated task. As for the fact that the two issues are linked and the second is supposed to be a ‘fix’ for the first… what can I say? Just goes to show that Apple’s software quality is declining and, at the same time, the company is willing to do just about anything to trick people into upgrading their iPhones.

Update: in the mean time we have confirmation from Apple for this finding, and got promptly hit with not one, not two, but three lawsuits. Naturally, Apple fans are defending the company to their last breath, no matter how ridiculous their arguments sound. During this ongoing debacle I remembered how a couple of months ago the same Apple fan press was raving about the iPhone’s benchmark results, calling it the fastest smartphone. It would certainly be interesting to track how fast this top performance is degrading over time. You can almost say Apple is intentionally overclocking their devices at launch, promoting them as fastest and most advanced, then reducing their performance to ‘average’ levels, thereby negating any advantage over Android smartphones.

The first unique characteristic separating Apple iPhones from other smartphones is that Apple is using a custom CPU architecture that differs a lot from those of other vendors. It’s plausible that the architecture is able to power down and power up in a much more aggressive fashion compared to other designs and as such has stricter power regulation demands. If this is the case then another question rises is if this is indeed just a transient load issue why the power delivery system was not designed sufficiently robust enough to cope with such loads at more advanced levels of battery wear? While cold temperature and advanced battery wear are understandable conditions under which a device might not be able to sustain its normal operating conditions, the state of charge of a battery under otherwise normal conditions should be taken into account during the design of a device (Battery, SoC, PMIC, decoupling capacitors) and its operating tolerances.

If the assumptions above hold true then logically the issue would also be more prevalent in the smaller iPhone as opposed to the iPhone Plus models as the latter’s larger battery capacity would allow for greater discharge rates at a given stable voltage. This explanation might also be one of many factors as to why flagship Android and other devices don’t seem to exhibit this issue, as they come with much larger battery cells.

Andrei Frumusanu

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