Laggy iPhone when recording 4k

Hello nikolaos176,

Welcome to Apple Support Communities. 

We understand that your iPhone runs slow slow when using AirPlay or recording in 4K. We are happy to help.

Please try the steps here: If your iPhone or iPad is running slow - Apple Support

1. "Check your network conditions
2. Close an app that's not responding
3. Make sure you have enough storage
4. Turn off Low Power Mode
5. Keep your device from getting too hot or cold
6. Look at your battery health"

These steps may help. Let us know if you have further questions.

Take care.

I have the exact same problem. The above issue can be easily replicated on all iPhone 14 even on latest iOS today.

The screen mirroring will start smooth, and stutter start 2 sec after. After another 2 seconds, the screen mirroring stutter badly and only update once in every 4-5 seconds.

Why do I do that? I have an external monitor connected to my Iphone 14 Pro through Screen Mirroring. I try to record professionally just like how you advertise iPhone 14/15. And I am stucked now with the new external screen that I purchased with the assumption screen mirroring should work when recording 4K.

This works perfectly on Samsung S22 with SmartView to cast the screen smoothly to my external screen when recording at 4K 24/30/60.

This is a huge let down and disappointment for me that a 2 year old Samsung phone that was not advertised to shoot professionally can perform that without breaking a sweat and I can't do it on my iphone 14 pro. :(

I suspect it is a A15 Bionic limitation, that the hardware can't support 4K recording and screen mirroring at the same time?

Can you please validate with your A15 Bionic engineer?

Or is that iOS/software issue that your iOS engineer can fix?