2X FPS drop after spending 20 seconds (IOS 18)

Bugs
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1

Hi Babylon Community,

I’m encountering a serious performance issue on my iPhone 14 Pro Max (iOS 18). After about 20 seconds in the experience, the FPS drops sharply—from a stable 60 FPS down to 30, and even below 20 FPS in more complex scenes. This seems to be happening when both refraction and shadows are enabled.

Tested that issue on IOS 18.0.1, 18.1, 17.5.1 (iPhone 14 Pro Max)

Here’s the playground for reference:
[https://playground.babylonjs.com/#HH8T00#272]

Any insights or suggestions would be greatly appreciated. Thank you!

CC: @Evgeni_Popov

2

I just tested on my iPhone SE, iOS 18.1. I waited 2mn, and the fps didn’t change and stayed at 50 fps constant. Maybe there are power saving processes that trigger and reduce performance?

Let’s see if other people can reproduce your problem.

3

Thank you for taking a look.
No power saving at all.

But yes, it works on older devices for some reasons.

4

Same as @Evgeni_Popov, all stable at 50fps on iphone 13 iOS 18.1

5

Yo @vlayd16 Did you ever figure this out. I just got an Iphone 16 Pro and my scene drop from 60fps to 30 fps at 15 sec… Exactly 15 sec. My Iphone 11 with latest IOS does not do this is stable at 45 fps.

6

Not really, still struggling

7

I wonder if it goes in protection mode cause it overheats

8

Any ideas or possible solutions?

9

Like @sebavan I believe it might me an hardware security triggered after some seconds, to avoid overheats. A good test would be to try to cool down your smartphone on test, and check if it continues for longer time before FPS drop.

(For example, since iPhone 14 Pro Max is IP68, you should be able to run a test under cool water… If you dare :grin:)