M4 Pro MacBook Pro screen was at 30Hz when battery hit 20%

[RPB65]

As title says, my new MBP went down to 20% battery at which point I thought the screen was very 'choppy' when scrolling. My brain was like wtf? It didn't even look like my Air and was worse. Anyway using the https://www.testufo.com/refreshrate website that reported it at 30Hz! I mean come on, surely it shouldn't really need to drop below 60Hz for scrolling. That can't be that much of a battery ho.
Anyway I plugged in the charger and yup, straight back up to 120Hz so what's that about?
I can't be having that poor a display just because it's on 20% battery. Discuss..... 😆 Cheers, Richard.

 

[Sheepish-Lord]

Low power mode on any Apple device with ProMotion limits the refresh rate to 60hz max. Additionally, TestUFO doesn’t work properly in Safari and if you are using Chrome then it could be the variable refresh rate (VRR) being reported as 30hz since you’re just starring at a screen.

Bottom line, what you experienced is normal for the technology (VRR) and how Apple designed it when low power mode kicks in.

 

[RPB65]

Low power mode on any Apple device with ProMotion limits the refresh rate to 60hz max. Additionally, TestUFO doesn’t work properly in Safari and if you are using Chrome then it could be the variable refresh rate (VRR) being reported as 30hz since you’re just starring at a screen.

Bottom line, what you experienced is normal for the technology (VRR) and how Apple designed it when low power mode kicks in.

Thx for the reply, however when I moved onto say X or Facebook and started scrolling it had stayed at the same 30Hz so not impressed if it's going to do that every time I hit 20% battery. Especially when an Air stays at 60Hz and looks far better no matter what % battery it's at. Some days I just run low ya know. 👍🏻

 

[RPB65]

Nah this is so rubbish. Battery hits 20% and Promotion drops the refresh rate to 30Hz. That is shocking. No need for that when it could easily be at 60Hz the same as the Air.

 

[dmccloud]

TestUFO actually throws up a prompt in Safari that says "For 120 Hz MacOS/iPadOS, disable 'Prefer Page Rendering Updates near 60fps'." On my MBP, it runs at a locked 120fps in Firefox and Chrome, but only 59-60fps in Safari. Chrome does have some occasional stuttering, so Firefox really is the only browser on my machine properly running that test. There have been issues with TestUFO misreporting framerates on MacOS going back to at least 2017, so this is not a new thing from that site.

 

[RPB65]

TestUFO actually throws up a prompt in Safari that says "For 120 Hz MacOS/iPadOS, disable 'Prefer Page Rendering Updates near 60fps'." On my MBP, it runs at a locked 120fps in Firefox and Chrome, but only 59-60fps in Safari. Chrome does have some occasional stuttering, so Firefox really is the only browser on my machine properly running that test. There have been issues with TestUFO misreporting framerates on MacOS going back to at least 2017, so this is not a new thing from that site.

I think my issue is that it drops the frame rate below 60Hz and I have compared it to my MBA I have. Another website (https://www.vsynctester.com/detect.html) also reported this was well. 30Hz is pathetic whether the battery is at 20% or not. Sometimes it's going to be low and for an expensive Mac I didn't expect that.