[illiac786]

Interestingly, in iOS 18, suppressing transparency (there’s a setting for it) makes performance worse, not better. The UI lags significantly more with transparency disabled. I expect it will be the same with iOS 26: there will be setting to reduce the transparency (which I find highly distracting) but it will make performance actually worse…

[citrin_ru]

Thanks for this insight. It's very counter intuitive. Normally transparency is additional work for a GPU.

I had "Reduce Transparency" check-box in settings turned on because I distaste semit-transparent interfaces. Was not noticing performance problems except one application - Ogranics Maps which were unusably slow after switching to another app and returning to maps so I had to restart it freqently (swipe up). I was thinking that the problem is with Ogranics Maps code.

After seeing this comment re-enabled transparency (iOS default) and Ogranics Maps working fast even if I switch between Organic Maps and other apps!

[illiac786]

It potentially only applies to older iPhones, I have an iPhone 12, what’s yours?

Also reported here for example:

https://www.reddit.com/r/iphone/comments/1d2ncvu/if_your_old...

[citrin_ru]

I use iPhone SE 3rd gen, accordig to wikipedia it's on A15 Bionic SoC, newer than in iPhone 12 (A14 Bionic) but still far from the latest.

[krferriter]

Did suppressing transparency also turn on processor throttling or something too? Like putting the device in a power saver mode?

[illiac786]

My phone is always in power save mode. Re-enabling transparency actually made the UI less jerky. It was mostly the keyboard that became unresponsive, I could type 15-20 letters while it froze and it would then „catch up“.

Also reported here for example: https://discussions.apple.com/thread/255911835

Re-enabling transparency improved this a lot, also keyboard still hangs a bit from time to time. I’m always in power save mode, on an iPhone 12, running iOS18.