Screen Refresh Rate and its impact on Smartphone Battery life and Performance
At ViserMark, we have been testing devices for almost a year now. We have been following the introduction of higher refresh rate displays very carefully as this new technology is directly impacting battery life.
Device manufacturers these days are looking for several ways to differentiate their devices by offering various features such as optimised battery life, enhanced cameras, 4K screens and recently high-end devices have included super-fast 90Hz to 120Hz refresh rates displays. Before we start analysing the impact let's explain what refresh rate is.
What is refresh rate?
What we need to understand is that smartphone displays are not static. The content in our devices appears very smooth and this is because every pixel in the display updates not randomly but at regular intervals which are known as a refresh rate.
Why do refresh rates matter?
A higher refresh rate will give a smoother experience when consuming certain content from your smartphone. You will get less value from steady usage content like looking at pictures, reading an article or email, during calls or even enjoying a short video. But for all usages with high screen transition, the comfort a user will experience from a higher refresh rate will be unmatched: browsing, scrolling within social apps, navigating through smartphone menus, searching for emails and gaming. In fact, high refresh rates were firstly introduced on gaming-focused smartphones (like the Razer Phone) and have progressively migrated to the premium segment, then into several more devices.
After using a smartphone with a 90Hz to 120Hz refresh rate you will find it exceedingly difficult to switch back to 60Hz (the standard rate) as the quality of experience is noticeably enhanced.
But this optimum performance for user experience comes with its drawbacks. Higher refresh rates require extra power, meaning a direct negative impact on battery life and performance. At ViserMark we measure this impact and aim to provide guidelines in our reviews on how to deal with this parameter.
We have been testing two different phones: the Oppo Find X2 Pro which holds an excellent 120Hz Quad HD and the Xiaomi Mi10T Pro with one of the only LCD screens able to refresh up to 144Hz. We have selected two cases where the screen must manage a fast refresh to keep up with the following user interaction: scrolling up/down in Gmail mailbox and browsing through chrome selection of articles.
Here are our findings:
On Gmail browsing, we measured around 10% extra power drain when switching from 60Hz to 120Hz
During Chrome browsing, we have measured up to 30% extra power drain when selecting 144Hz
(Power drain during Chrome browsing: 60Hz in blue / 144 Hz in black on Redmi 10T Pro)
As you know, the impact on battery life can be rather important. Although enabling a higher refresh rate will lead to shorter battery life, you can not conclude that the overall usage time will be reduced by up to 30%. Indeed, manufacturers have implemented an interesting feature to help you get the best experience with minimum impact on power drain: adaptive refresh rate. This means that the smartphone will adapt its refresh rate depending on the user activity. Furthermore, while the previous adaptive feature was switching between 60Hz, 90Hz or 120Hz, brand new premium displays are integrating a new adaptive algorithm. Which, can choose within a broader range of rates, from 10Hz to 120Hz, ensuring the balance between smoother experience and control of battery life.
In conclusion, the latest display technologies around refresh rate are highly changing the user experience. While manufacturers are very cautious not to affect the impact on battery life, we recommend sticking to lower refresh rates for busy days where battery percentage remains key. This will ensure you prolong the battery life when you need it most.
Further results will be shared in the coming months with performance on specific devices, chipsets, and Network Operators.