Here's why your old iPhone feels slow -- and what you can do about it

It's got nothing to do with Apple doing something underhanded such as deliberately throttling your iPhone to tempt you to buy a new one.
Written by Adrian Kingsley-Hughes, Senior Contributing Editor

The other day benchmarking firm Futuremark published a report that attempted to put an end to the long-held urban legend/conspiracy theory that Apple deliberately throttles old hardware in an attempt to encourage owners of old iPhones to upgrade.

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Now, of course, this urban legend is hogwash. There's never been any evidence to suggest that Apple has been doing anything of the sort, and it's all based on anecdotal evidence.

But the idea that iPhones get slower as they become older is not a myth. In fact, the longer you use it, the more sluggish it gets. Actions such as unlocking the iPhone or firing up an app become appreciably slower.

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The problem is that cache files and other detritus builds up over time, much like it does on a computer.

And it is, in part, a reversible problem. Wiping your iPhone and starting from scratch helps a lot, and doing what's called a DFU Mode upgrade appears to be even better. I find doing this yearly on older hardware helps a lot.

But there's another reason, and it has to do with how much more processor power each iteration of the iPhone or iPad offers both Apple and developers. This chart from Geekbench shows just how much more powerful the newer hardware is compared to even the previous-generation hardware.

​Geekbench benchmark results for iOS devices

Geekbench benchmark results for iOS devices


More power means that Apple will cram more and higher-performance features into new iOS releases. It also means that app developers will be creating more demanding apps.

All this puts an inevitable pressure on old hardware. And just like a desktop or laptop, what was once fast feels slow.

It's just a fact of life. New software puts a greater load on older hardware. And while there are some things that you can do to lessen the effect this has, ultimately it's an inevitable process.

Stuff gets older and we have to replace it.

When the iPhone 7 landed a little over a year ago, its CPU was 120 times faster than the original iPhone, with the GPU being a whopping 240 times faster, and yet now, one generation on in both hardware and iOS releases, I'm hearing from people who feel that their device is showing its age.

I think that it's also worth pointing out that if indeed Apple was throttling older hardware, it's more than likely it would do it in such a way that it wouldn't show up during a benchmark. Earlier this year handset maker OnePlus was caught cheating at benchmarks for a second time. And the fact that the cheating was uncovered means that a high-profile company such as Apple wouldn't want to have its reputation damaged by being caught out either throttling performance or cheating at benchmarks.

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