What does `Enable ProMotion Support` actually do?

[FadiObaji]

I tried checking/unchecking this checkbox and build the game, tried it on iPad pro 13" and iPhone 13 pro. (Unity 2019.4.30 LTS)

The iPad pro runs the game on 120hz with and without the checkbox checked.
The iPhone 13 pro runs the game on 60hz with and without the checkbox checked!

I tried looking this up in Unity Docs, it’s saying that:

Enable this option to allow high frequency refresh rates (120 Hz) on ProMotion displays. Enabling this setting might affect battery life.

Well, it’s not doing that.

It feels like this feature is not doing anything at all?

[AcidArrow]

You also need to set target frame rate to 120 ( Unity - Scripting API: Application.targetFrameRate ).

[FadiObaji]

@AcidArrow

You also need to set target frame rate to 120 ( https://docs.unity3d.com/ScriptReference/Application-targetFrameRate.html ).

I did, didn’t work!

[FadiObaji]

I also found that there are some stuff that you need to do in Objective-C for that to work, read here
I think Unity is not doing that when checking this chekbox!

[AcidArrow]

Hmm… It does work for me and I don’t think I’m doing anything else framerate related, although I am using 2020LTS instead of 2019LTS.

[AcidArrow]

@FadiObaji

I also found that there are some stuff that you need to do in Objective-C for that to work, read here
I think Unity is not doing that when checking this chekbox!

I think it does do that actually, but maybe it’s a 2020+ feature?

The original promotion feature was intended for iPad Pro. iPhones have it implemented a bit differently, maybe 2019 doesn’t have that feature?

[AcidArrow]

Here you go: Unity Issue Tracker - "Enable ProMotion Support" does not allow iPhone 13 Pro/Pro Max to run at higher refresh rates

RESOLUTION NOTE (FIX VERSION 2019.4):
Fixed in 2019.4.33f1

You just need a slightly newer version from what you’re using.

[FadiObaji]

@AcidArrow

I think it does do that actually, but maybe it’s a 2020+ feature?

The original promotion feature was intended for iPad Pro. iPhones have it implemented a bit differently, maybe 2019 doesn’t have that feature?

Interesting! I think if you have it working on 2020 LTS, then it does not work with 2019 LTS, I found a solution to make it work tho, it’s here and it works.

But I wanted to ask you, does the iPhone 13 suddenly goes to 60hz and then suddenly goes back to 120hz? this is what’s happening sometimes after doing what’s in the url I provided.

[FadiObaji]

@AcidArrow

Here you go: https://issuetracker.unity3d.com/issues/enable-promotion-support-does-not-allow-iphone-13-pro-slash-pro-max-to-run-at-higher-refresh-rates

RESOLUTION NOTE (FIX VERSION 2019.4):
Fixed in 2019.4.33f1

You just need a slightly newer version from what you’re using.

THANKS ALOT!

[AcidArrow]

@FadiObaji

But I wanted to ask you, does the iPhone 13 suddenly goes to 60hz and then suddenly goes back to 120hz? this is what’s happening sometimes after doing what’s in the url I provided.

I had tried the method in that link and framerate was really unstable.

I think it’s less unstable with Unity’s implementation (although I didn’t do a side by side), but it still drops to 60 occasionally even though it could afford to stay at 120. I think it looks fine though.

[FadiObaji]

@AcidArrow

I had tried the method in that link and framerate was really unstable.

I think it’s less unstable with Unity’s implementation (although I didn’t do a side by side), but it still drops to 60 occasionally even though it could afford to stay at 120. I think it looks fine though.

Hmm, I think this is because Apple said that a ProMotion display is different that other 120hz displays and that IT decides what framerate to display.

[Neonlyte]

@FadiObaji

I found a solution to make it work tho, it’s here and it works.

Hi there. I wrote that thread.

I would assume iOS is very aggressive on power consumption. iPhone’s battery and volume is much smaller than iPad, so it has smaller battery and it can not dissipate heat as fast.

TBH even when the game do run at 120Hz, on a small screen it’s just isn’t that noticeable. When it flips between 120Hz and 60Hz a difference can be observed, but not having 120Hz at any time is not a big loss at all. For my project I’m not going to bother adopting it for iPhones.

Before Unity supported iPad Pro’s 120Hz refresh rate I patched that same call site with the relevant API and it has just been working. I don’t think there would be a different way of doing the fix this time.

Edit: I checked. Unity’s patch is semantically identical to mine. This screenshot is taken from 2021.2.7 iOS Support:

[FadiObaji]

@Neonlyte

Hi there. I wrote that thread.

I would assume iOS is very aggressive on power consumption. iPhone’s battery and volume is much smaller than iPad, so it has smaller battery and it can not dissipate heat as fast.

TBH even when the game do run at 120Hz, on a small screen it’s just isn’t that noticeable. When it flips between 120Hz and 60Hz a difference can be observed, but not having 120Hz at any time is not a big loss at all. For my project I’m not going to bother adopting it for iPhones.

Before Unity supported iPad Pro’s 120Hz refresh rate I patched that same call site with the relevant API and it has just been working. I don’t think there would be a different way of doing the fix this time.

Edit: I checked. Unity’s patch is semantically identical to mine. This screenshot is taken from 2021.2.7 iOS Support:

Thank you for your reply, I too will not bother adapting to the iPhone’s 120HZ because like you said it’s not always at 120hz like the iPad and it’s not very different than 60hz.

Thank you.