Google does not allow certain apps to use the Pixel 4’s “Smooth Display” feature to operate at 90Hz. The blacklist was disclosed in the source code of the Pixel 4 and Pixel 4 XL. The apps are Google Maps, Pokemon Go, Waze, and WeChat.

It is not known whether these apps are in fact unable to run at 90Hz or not, but it has confirmed that Google Maps and Waze only run at 60Hz on a Pixel 4. For these apps, the ban is not. not a surprise as they regularly drain the battery and therefore have to continue operating at a 60Hz limit. They simultaneously use the phone’s GPS, GPU and cellular radio while keeping the screen active. If they operate at 90Hz, they will drain the battery further.

Maybe one day Google will let these apps run at 90Hz.

It doesn’t make sense for Google to keep WeChat behind, however, as the Pixel 4’s source code mentions “poor performance” at the highest refresh rate of 90Hz.

Smooth Display was not received as well as Google hoped. Earlier in the week, some users noticed that the Pixel 4’s refresh rate drops to 60Hz when the brightness is above 75%. Google anticipates that 90Hz rates will be available once the Smooth Display is in place. The answer to this problem could be the commits found in the source code of Android 10 – the screen would flicker with a change in refresh rate.

The display uses different gamma curves for different refresh rates. The panel supplier would not be able to adjust the curves to match the brightness for different brightness rates. A flicker would then be visible to the user. The problem is greater when the gamma is at its lower end, because human eyes could see the flicker better in a darker location.

In order to avoid flickering, high refresh rates are better accepted in brighter ranges.

Hoping that Google is working on the problem and sending a software update to allow us to use the Smooth Display at a lower brightness and that we can get back to optimal use of our apps.