iOS 9: Will upgrade break my old iPhone?

New iOS versions used to play havoc with the elder iPhone generations, but this year, things are looking up

How does Apple get people to keep buying new iPhones? One theory says it’s planned obsolescence. New versions of the iOS system software have a reputation for running so slowly on older phones, you’re basically bullied into buying a new one.

Apple says that ain’t so, and that it optimised this year’s upgrade to iOS 9 — available as a free update, with new capabilities and power savings — to work even on devices that came out in 2011.

So I put iOS 9 to the test on four generations of iPhones: 4S, 5, 5S and 6. I found that this year at least, Apple’s software isn’t to blame for your existing phone seeming positively geriatric.

Another thing that owners of older — and cheaper — iPhones should note: Apple slimmed down the iOS installer this year, from 4.58 GB down to 1.3 GB. This makes it easier for upgraders to get iOS 9 without having to delete precious photos or crucial apps.

FULL REVIEW: iOS 9 Upgrade

Testing Four Generations of iPhones

In my tests, iOS 9 slowed down the entire line-up of iPhones by only a negligible amount. And in one important area, dealing with photos, it actually speeds them up a lot.

I loaded each guinea pig phone with iOS 8.4.1 — the last of the eights — and timed the same motions on each. My tests included booting up to the lock screen, launching the Camera app, launching the Safari browser and looking at a photo I just took. I did each of these at least three times, and sometimes many more, and calculated the mean result. (I forced-closed apps after each test.)

Then I loaded the final version of iOS 9 on each handset, and did it all over again.

Opening most apps on all these phones either didn’t change or got just a hair slower. For example, launching Safari on the iPhone 5S took ... a quarter of a second longer with iOS 9.

The biggest single performance slip I recorded was on the iPhone 5, where the cold boot up took three seconds longer on iOS 9 than it did on iOS 8.

In the writer’s tests, the iOS 9 upgrade slowed down the entire line-up of iPhones, including the pictured iPhone 5, by only a negligible amount. Credit: Getty

The Photos Fix Is In

iOS 9 also fixes a bug on iOS 8 that affected how quickly you can view or edit a photo after taking it. This painful slowdown snuck onto iPhones after Apple introduced iCloud Photo Library earlier this year.

With iOS 9, looking at a photo is about 80 per cent faster, no matter how old your phone is. The iOS 9 upgrade is worth it just for this fix, but there are lots of other reasons to get it, too.

Both iOS 7 and iOS 8 came out initially in versions that weren’t tuned well to older phones, and caused owners to report slower performance, among other problems. Apple eventually came up with updates to both that sped things up for older phones.

This time around, it made iOS 9 a public beta, allowing it to get lots and lots of feedback about performance issues.

None of this is to say you shouldn’t upgrade your hardware — especially if you have a need for speed. I was surprised to see how opening an app is, on average, three times faster on an iPhone 6 than on a 4S. That feels like an eternity in 2015.

Wall Street Journal