Linked by Thom Holwerda on Wed 20th Dec 2017 17:36 UTC

A Reddit post from last week has sparked a discussion regarding iPhone performance as a function of battery age. While we expect battery capacity to decrease as batteries age, we expect processor performance to stay the same. However, users with older iPhones with lower-than-expected Geekbench 4 scores have reported that replacing the battery increases their score (as well as the performance of the phone). What's going on here? How many phones are experiencing decreased Geekbench 4 score?

To answer these questions I've plotted the kernel density of Geekbench 4 single-core scores for the iPhone 6s and the iPhone 7 running different versions of iOS. Scores obtained in low-power mode are not included in the distribution.

Evidence seems to be mounting that Apple is decreasing the clock speed of iPhones with decreased battery capacity to maintain the advertised battery life.

Thread beginning with comment 652249
To read all comments associated with this story, please click here.
Makes sense from a business perspective
by darknexus on Wed 20th Dec 2017 18:09 UTC
Member since:

If true, this is a sensible business move. Note that I'm not taking a stance on the ethics of this decision, just saying it would make a great deal of sense. In one stroke they maintain the battery life of older devices, make those devices feel slower and therefore encourage upgrades, and on top of that they are able to say (quite truthfully) that iPhones will keep the same battery life better than any other phones on the market. From a money making perspective, it's brilliant--so brilliant that I hesitate to believe it given Apple's notable lack of business sense in the past few years.

Reply Score: 4

Alfman Member since:

Who knows, it could be planned obsolescence, what companies do doesn't really surprise me at this point. I would want to conclusively rule out other possible causes to establish real causality and not merely correlation. For example, we know that flash storage becomes slower with use (as the used cells take longer and longer to program as they resist change). Has anyone conclusively proven that flash performance does not impact the geekbench scores?

I don't have an IOS device, but anyone who does could perform this test, and I'd be very curious what the results are:

Measure performance with old battery, full charge and plugged in.
Measure with full charge, unplugged.

Measure with low charge, unplugged.

Measure with low charge, plugged in.

If possible replace with new battery and repeat tests.

It's possible that the iphone is programmed to conserve power on low battery, an old battery will spend a greater amount of time running at relatively lower voltage. But when it's plugged in this should not be the case. If the iphone performance suffers even when it's plugged in and full charge, then the odds are high that planned obsolescence is at work.

Apple could fix it with an update, but at the same time, fixing it is kind of an admission of their guilt.

Edited 2017-12-20 21:39 UTC

Reply Parent Score: 3

CaptainN- Member since:

It's not planned obsolescence, since a new battery restores the old performance characteristics.

This doesn't seem nefarious to me at all. It's annoying, and it's not the decision I would have made, but it's a sound decision. There are two possible ways to deal with the problem. Accept decreased battery life to maintain performance, or decrease performance to maintain battery life. The two options are mutually exclusive, and Apple is the kind of company that prefers to avoid burdening users with those kinds of decisions.

Still, I wish they'd included an option to toggle the behavior. Old slow iPhones suck, and literally, have caused me to advocate for Android because they don't slow down (I had presumed with iOS releases, though now the evidence shows a different reason). I'm probably not the only one.

Reply Parent Score: 3