In today’s edition of Tech InDepth, we’ll look at how LTPO panels and non-LTPO panels work, and how the tech helps your high refresh rate phones save battery. We will also understand the difference in the working of these two technologies and which one is better for you.
What is 60Hz, 90Hz and 120Hz?
In the context of smartphones and display panels, 1Hz refers to a display panel that refreshes once per second, a 60Hz panel refreshes 60 times per second, and so on. The higher the refresh rate, the more battery the screen consumes in the same amount of time. Smartphones don’t always have high refresh rate content to display. If you’re playing a game that maxes out at 60fps on a 120Hz display, you’re still seeing 60fps, even though the screen is refreshing twice as much per second. It’s like watching a regular movie with 3D glasses, where the picture won’t give you 3D effect because it doesn’t have it and your glasses don’t help by themselves.
Phones like the Nothing(1) phone have two “zones” to facilitate this (60Hz and 120Hz), while phones like the Redmi K50i have seven zones (30Hz, 48Hz, 50Hz, 60Hz, 90Hz, 120Hz, and 144Hz), allowing it more flexibility to switch between these areas depending on the content. These areas work like gears on an automatic AMT car. There’s no need for a clutch, but the gears change internally based on your engine’s rpm. Similarly, phones with dynamic refresh rate switching use software to understand what content is being displayed and, accordingly, choose one of the predefined areas. More zones mean more flexibility in switching and therefore more energy saving, while fewer zones mean less flexibility and less energy saving.
On LTPO display panels, the panel itself can intelligently switch between no predefined zones, but each refresh rate between its minimum and maximum refresh rate. On newer LTPO 2.0 panels, the minimum and maximum refresh rates are typically 1Hz and 120Hz respectively. LTPO panels offer significant battery savings on phones compared to non-LTPO panels. Things don’t make a major difference on higher refresh rates like when gaming, but in more casual use cases the LTPO panels are much more dynamic. For example, when watching a still image, the non-LTPO panel will always refresh at least 60 times per second, while the LTPO panel will operate at 1Hz, only refreshing once per second.