Google’s changes to 90Hz display affect Pixel 4 and 4 XL differently

One of the controversies surrounding Google’s Pixel 4 and 4 XL at launch was how both devices handled 90Hz displays.

Essentially, both the Pixel 4 and 4 XL restricted the 90Hz refresh rate when using the ‘Smooth display’ setting to conserve battery. Smooth display automatically adjusts the refresh rate based on content, but users discovered it factored brightness into the equation as well. Any time the screen fell below 75 percent brightness, it would fall to a 60Hz refresh rate.

Google promised a fix for the issue, which would come with the November security patch. It looks like the update brings some significant changes, but more so for the Pixel 4 XL than the 4.

According to XDA Developers, the Pixel 4 XL will stick with 90Hz regardless of the brightness level. In other words, only content will affect the display’s refresh rate. The Pixel 4, however, won’t get the same treatment. Instead, the smaller Google flagship will use 90Hz when above 42 percent brightness and the ambient brightness will not affect refresh rate.

Google’s decision to have more 90Hz display restrictions on the Pixel 4 likely comes down to battery life. However, users who want to get around the limitation can force 90Hz to stay on at all times. To do so, head to Settings > System > Advanced > Developer options > scroll to Force 90Hz refresh rate.

Has the udpate made a difference?

According to 9to5Google, the update has significantly improved the up-time of the 90Hz display.

9to5 ran an ADB command that shows how much time the 90Hz display is active on a Pixel 4 between reboots. Writer Ben Schoon, editor Abner Li and Cameron Summerson, editor-in-chief of Review Geek all participated in a test to compare the pre-update 90Hz display usage to the post-update usage.

Schoon saw about a 30 percent increase in 90Hz activity on his Pixel 4 XL, while Summerson only saw a 16 percent increase on his 4 XL. Before the update, both saw about 5 percent 90Hz display usage. Li, who used a Pixel 4 and locked the brightness at 50 percent, didn’t see any 90Hz usage before the update. Post-update, Li reported the 90Hz refresh rate was active for about 20 percent of his usage.

So, it looks like the update did improve how often the Pixel 4 and 4 XL use the 90Hz display. What remains to be seen is if the changes have a drastic impact on battery life.

"Only on the Pixel 4 XL when it's running at 90Hz and you turn off and on the display, it applies the wrong gamma table and the display looks ridiculously contrasty and very magenta-shifted." – Dylan Raga

Left: 60Hz / Right: 90Hz

Anyone else see this? pic.twitter.com/4de1HNf8A8

— Mishaal Rahman (@MishaalRahman) November 5, 2019

However, not everything in the update is good. XDA’s editor-in-chief, Mishaal Rahman, reports that the update worsened a bug on his Pixel 4 XL. The flaw applies an incorrect display gamma setting when you turn the screen on and off while it’s running at 90Hz. Because the 4 XL now runs at 90Hz more often, the bug happens more often as well.

At the time of writing, the bug hasn’t surfaced on either of the Pixel 4 XLs at MobileSyrup.

Source: XDA Developers, 9to5Google