Will iOS 18 slow down my iPhone?

[Zaft]

My 12PM feels the same on IOS 18! beta ad IOS 17.

I have an old XR and it’s definitely choppy now on iOS 18 Beta. So it just depends how old.

 

[Allen_Wentz]

I’ve been reading comments about how Apple Intelligence needs more RAM and only certain iPhones will support AI. That’s fine but what are the chances that iOS 18 will slow down those iPhones that won’t support AI? My reasoning is that if AI features will be ‘disabled’ on my iPhone 11 it should run just fine on iOS 18… right?

Short answer is yes, it is very very likely that iOS 18 will slow down older iPhones from 5 generations back. Especially the earliest dot versions of iOS 18. Whether any given user will notice or be offended by the slowing depends on YMMV.

The process of newer OS/apps running more slowly on old hardware has been happening inexorably since the beginning of tech. Each of us makes an individual decision as to when the slowing becomes problematic.

As others have noted, earlier dot versions of new OSs tend to be worse. If one has concerns one should generally avoid releases through X.1 and surf to see what other users' observations are before committing to an OS upgrade. E.g. for decades my personal upgrade rule was not to upgrade until at least X.3 with Mac OS, sometimes skipping an entire.OS version. Apple today however has much better control of OS/iOS/WatchOS upgrade versions and the base of installed users is so huge that IMO waiting/watching through X.1 is generally enough to determine if one wants to jump in or not.

 

[surfzen21]

I’ve been reading comments about how Apple Intelligence needs more RAM and only certain iPhones will support AI. That’s fine but what are the chances that iOS 18 will slow down those iPhones that won’t support AI? My reasoning is that if AI features will be ‘disabled’ on my iPhone 11 it should run just fine on iOS 18… right?

I have an iPhone 11 as my work phone. I am running the latest public beta of iOS18 and i find that the last two betas run better than when I had iOS17 on it.

This is my work phone and does not get used as much as my primary phone though.

 

[Tagbert]

Uhhhh
iOS 12 absolutely ruined my iPhone 6 Plus. It ran fine on iOS 9. iOS 12 made it slower than molasses. I jumped directly from iOS 9 to iOS 12, skipping 10 and 11, and the end result was a disaster.

iOS 9 ruined my iPhone 4S and everyone else’s It ran fine on iOS 8. Became way too slow.
iOS 10 ruined my iPhone 5. Became way too slow

How many examples do you want?
Apple has been sued hundreds of millions of dollars because of this intentional “ruining” of iPhones through iOS updates that they assured people were fine.
They have a long track record of wrecking iPhones.

Back in the day the chip performance was so slow that the phones were barely able to operate on software built for them. Year over year chip performance increases were significant as there was a lot of room for improvement. The 4s was noticeably faster than the 4 and 5s and 6s were also big improvements. In those days we tended to get a big performance bump on the ‘S’ phones. As new OS features were added it was harder and harder for the older chips to keep up. By the time we got into the 7, 8, and X generations the chips were getting fast enough that each generation was not a big jump over the previous and annual OS changes had less and less of a performance hit. It’s been years since OS upgrades were a serious performance concern.

 

[WarmWinterHat]

I always set my phone up as new when I install a new os. The only thing that carries over is contacts, texts and my passwords. I have to redownload every app and re-sign into them which is a pain, but it also helps me to get rid of the ones that I don’t have a need for anymore as well. That’s why I’m glad I do this on a Friday and have the whole weekend to do this painstaking process.

I've heard this for years and it's nonsense, at least from my experience. I've setup my phone as new, once, when I screwed up a jailbreak on an iPhone 4 and didn't have a backup. Since then, I've never installed new, and have no issues whatsoever; continuous upgrades since iOS 4.something.

Unless there is something wrong, it just doesn't matter. We're not running Windows 98.