I have got an iPhone 6S on October of 2015.

Sometime in 2016, I downloaded Geekbench 3, to benchmark the device.

My baseline results are: (5 runs)

Single: ~2500 (2450-2550)
Multi: ~4400

Now, I feel like my iPhone is becoming slower, so I did the benchmark again. (11 months later)

My new results are: (5 runs)

Single: ~1500 (1200-1800)
Multi: ~2100

And it seems that it is somewhat dependent on the battery percentage (low battery => low result. but even 100% battery is ~1700)

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I understand these are synthetic benchmarks, and are not fully representing the device's performance, but it seems odd, and I want to know if my device is defective? Do I have a case for a phone replacement? Or, am I reading too much into it, and devices just decay over time?

Note: I'm not sure if this is relevant, but my device is part of the apple recall for battery replacement, but because the apple re-seller in my country does not supply phone replacement, I did not change it.

  • @books453 Visible on the image. iOS 9.3.2 / 10.3.1
    – Amit
    Apr 23, 2017 at 20:14
  • oh sorry I didn't notice that.
    – airsquared
    Apr 23, 2017 at 20:17
  • I don't understand the following: my device is part of the apple recall for battery replacement, but because the apple re-seller in my country does not supply phone replacement, I did not change it. This was a recall to replace the battery, not the phone itself. Regardless, if you're eligible just phone Apple and they will make an appointment/arrangements to action the recall. That should be the first thing you do. Both mine and my wife's iPhone 6s batteries were replaced and this adds quite a bit of longevity to the phone.
    – Monomeeth
    Apr 23, 2017 at 20:58
  • @Monomeeth I understand I need to replace the battery, but I am not sure that this is why performance is down. I didn't replace because for the 5 days it's gonna be in the lab, I won't have a phone
    – Amit
    Apr 23, 2017 at 20:59
  • 1
    Yes, but troubleshooting is a process of elimination and in your case replacing the battery is one obvious place to start. You've already stated that your Geekbench results seem somewhat dependent on the battery percentage, so presumably this will make a difference. Another factor that can impact scores include whether your phone is in low power mode (usually reduces single core scores by about 36% and multi core scores by roughly 39%). My iPhone 6s typically gets just over 2500 for single core and around 4400 for multi core scores. It's on iOS 10.3.1 and has a new battery from the recall.
    – Monomeeth
    Apr 23, 2017 at 22:00

2 Answers 2


It would appear to be an intentional change in how the phones perform as the battery ages, to prevent early shutdown in exchange for slower performance.

From Geekbench - iPhone Performance and Battery Age

Performance and Battery Age So what’s going on here?

First, it appears the problem is widespread, and will only get worse as phones (and their batteries) continue to age.

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. Why did Apple do this? kadupse on Reddit offers the following explanation:

"Many iPhone 6s devices were shutting down unexpectedly, even after the battery replacement program (Which many people weren’t entitled to use). Because degraded batteries last much less and end up with a lower voltage Apple’s solution was to scale down CPU performance, it doesn’t solve anything and is a bad experience… but it’s better than having your device shutdown at 40% when you need it the most."

Apple acknowledged the sudden shutdown issue that affected the iPhone 6 and iPhone 6s earlier this year. However, does the same issue affect the iPhone 7? Apple appears to have added a similar change to iOS 11.2.0 for the iPhone 7.

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 obsolecense” narritive.


Your answer is on this post on the geekbench blog. Pretty nasty of Apple to do this secretly. https://www.geekbench.com/blog/2017/12/iphone-performance-and-battery-age/

  • 1
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    – fsb
    Dec 19, 2017 at 14:23
  • Just bought an iPhone X and 2 hours ago sent my 6s for battery replacement. Thanks!
    – Amit
    Dec 20, 2017 at 13:52

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