THE IMPACT OF HIGH REFRESH RATE SCREENS (120HZ, 144HZ) ON SMARTPHONE BATTERY LIFE

The integration of high refresh rate displays, such as ¹$120$Hz and ²$144$Hz panels, into modern smartphones represents one of the most significant and immediately noticeable hardware upgrades in recent years, fundamentally transforming the user experience with its silky-smooth scrolling and superior gaming performance.³ Refresh rate, measured in Hertz (Hz), refers to the number of times per second the screen updates the image, with ⁴$120$Hz updating the screen twice as often as the previous standard of ⁵$60$Hz.⁶ While the resulting visual fluidity is undeniably appealing, particularly for competitive mobile gamers and users who prioritize responsiveness, this dramatic increase in image updates imposes a substantial and direct power consumption penalty, making it one of the largest drains on a smartphone's finite battery capacity. The trade-off between the premium visual experience and the fundamental need for all-day battery life has become a critical balancing act for manufacturers, leading to the development of sophisticated adaptive technologies aimed at mitigating this power demand without sacrificing the core user benefits.⁷

A higher refresh rate inherently translates to a greater workload for the smartphone's core components, which collectively contribute to the increased battery drain.⁸ It is not simply the display panel itself drawing more power, though that is a significant factor, but also the Display Driver IC (DDIC) and the device's main CPU and GPU that must work harder and faster to support the accelerated screen updates.⁹ The graphics processing unit must render twice the number of frames per second to fully utilize a $120$Hz panel, while the central processing unit must dedicate more resources to track touch input and manage the application's faster rendering pipeline. Furthermore, the DDIC, the component responsible for translating the data from the GPU into signals for the display, must communicate at a much higher bandwidth, leading to increased power draw even when the content on the screen is static.¹⁰ This synergistic power increase across multiple subsystems means that switching from $60$Hz to a fixed $120$Hz can reduce a smartphone's overall endurance by a measurable percentage, which in some real-world tests has been shown to result in a reduction of one or more hours of total screen-on time.

THE FUNDAMENTAL POWER DEMAND OF FASTER REFRESH

The primary reason a high refresh rate drastically increases battery consumption is rooted in the basic physics of display operation, which necessitates the display drawing a new image multiple times every second, regardless of whether the content has changed. A $60$Hz display needs to draw $60$ frames in one second, requiring a period of approximately $16.7$ milliseconds per frame, whereas a $120$Hz panel demands $120$ frames in the same second, cutting the frame time down to a mere $8.3$ milliseconds. This doubling of the refresh cycle puts an immediate and continuous strain on the hardware, forcing the display panel’s pixels to be re-energized and refreshed more frequently, which draws more power from the battery.¹¹ The effect is constant, applying not just when fast-moving content like games or animations are displayed, but also when the user is simply scrolling through a static web page or browsing through application menus.¹²

This power consumption penalty is especially pronounced on mobile displays that rely on traditional fixed refresh rate modes, such as the early implementations of $90$Hz and $120$Hz screens, which were locked to the high rate regardless of the displayed content. When a user is viewing a static image, reading an e-book, or pausing a video, the screen is still refreshing the identical image dozens of times per second, an action that serves no visual purpose but continues to expend precious battery life. The circuitry that drives the display, including the aforementioned Display Driver IC, continues to operate at the high-frequency signal rate to maintain the potential for a rapid update, leading to substantial energy wastage over the course of a day.¹³ This realization quickly led manufacturers to acknowledge that the pursuit of ultra-smoothness without intelligent power management was economically unviable for devices marketed for all-day use. Consequently, the industry has been driven toward developing sophisticated technologies that dynamically adjust the refresh rate to match the content's actual requirement, thereby conserving power without compromising the ultimate viewing experience.¹⁴

INCREASED WORKLOAD ON CPU AND GPU SUBSYSTEMS

The power drain attributed to a high refresh rate extends far beyond the display panel itself, significantly impacting the workload and energy demands of the smartphone's CPU (Central Processing Unit) and GPU (Graphics Processing Unit), which are the primary engines responsible for generating the visual content.¹⁵ For the full benefit of a $120$Hz screen to be realized, the GPU must be capable of rendering graphics and animations at a minimum of $120$ frames per second (FPS). This requirement demands that the GPU runs at consistently higher clock speeds and maintains a heavier computational load than it would for a $60$FPS target, directly correlating to a higher rate of power consumption. The increased workload is particularly acute during graphically intense activities such as competitive mobile gaming, where the GPU operates near its peak capacity, rapidly draining the battery and often contributing to higher device temperatures, which further exacerbates the power efficiency problem.

The CPU is also heavily implicated in this increased power consumption because it manages the system's overall frame delivery pipeline, including handling rapid touch input and coordinating the operating system's interface animations.¹⁶ When the display operates at ¹⁷$120$Hz, the CPU's input handling threads must also work twice as fast to register and respond to screen touches in a much shorter timeframe, ensuring that the touch-to-display latency is minimized to maintain the feeling of responsiveness.¹⁸ Even minor tasks, such as tracking the user's finger during scrolling, demand more frequent processing cycles from the CPU to keep up with the doubled refresh rate of the screen.¹⁹ This constant need for higher throughput from both the GPU for rendering and the CPU for system control means that the energy used by the application processor subsystem increases notably when a fixed high refresh rate is enabled.²⁰ This combined power penalty from the display hardware, the DDIC, the CPU, and the GPU explains why the difference in total battery life between a fixed $60$Hz mode and a fixed $120$Hz mode can be so substantial, far greater than the power cost of just the screen refreshing itself.

THE ADAPTIVE REFRESH RATE SOLUTION

To effectively address the critical power consumption issue inherent in high refresh rate technology, manufacturers have pioneered and widely adopted Adaptive Refresh Rate systems, most notably implemented through LTPO (Low-Temperature Polycrystalline Oxide) display technology.²¹ LTPO is a specialized type of OLED panel backplane that is engineered to enable the display's own control circuitry to dynamically and intelligently adjust the refresh rate across a wide spectrum, often ranging from an ultra-low $1$Hz up to the maximum $120$Hz or $144$Hz peak. This technology is the most important development in balancing high-end visual performance with energy efficiency, allowing the screen to deliver the smooth, high-speed experience when necessary while conserving massive amounts of battery power when it is not.

The core mechanism of LTPO hinges on the idea that the user only requires the maximum refresh rate during fast motion, such as scrolling through web content, watching high-frame-rate videos, or playing performance-demanding games. When the phone is static—for example, displaying a photograph, showing the lock screen's Always-On Display, or viewing a static text page—the display controller can dramatically slow the refresh rate down to as low as $1$Hz. By reducing the refresh cycle to once per second, the power consumption of the screen, the DDIC, and the supporting system components is drastically reduced, as the device is no longer constantly re-energizing the same pixels $120$ times every second. Modern flagship smartphones utilize sophisticated software algorithms that continuously monitor the content on the screen, intelligently throttling the refresh rate to the absolute minimum required—perhaps $10$Hz for static text, $24$Hz for standard video playback, $60$Hz for system menus, and only hitting $120$Hz during gaming or fast navigation. This dynamic and fractional refresh management system has largely nullified the massive, fixed battery drain that plagued earlier generations of high refresh rate panels.

DIMINISHING RETURNS AND FUTURE EFFICIENCY

While the leap from $60$Hz to $120$Hz provided a revolutionary, highly visible improvement in motion clarity and responsiveness, the subsequent increase to even higher rates, such as $144$Hz, $165$Hz, or $240$Hz, currently available mainly on dedicated gaming smartphones, offers increasingly diminishing returns for general battery life. The power consumption curve, which saw a significant jump when moving from $60$Hz to $120$Hz, continues its upward trajectory with each step, but the corresponding increase in perceived visual smoothness for the average user becomes minimal. The difference between $120$Hz and $144$Hz is far less noticeable than the difference between $60$Hz and $120$Hz, yet the system is still required to render and refresh an additional $24$ frames per second, further increasing the burden on the GPU and the display hardware.

For the vast majority of consumer content, including system animations and most video games, the frame rate is often capped at $60$FPS or $120$FPS due to content limitations or thermal constraints, rendering the extra capacity of a $144$Hz or $240$Hz panel technically wasteful in terms of power consumption. When a game runs at $60$FPS on a $144$Hz screen, the display is drawing the same image $2.4$ times for every new frame of content, which directly translates to unnecessary energy expenditure. Therefore, even with advanced adaptive technology, the presence of a higher maximum refresh rate capability suggests a higher potential peak power consumption when the device is running a compatible game or application that is able to utilize the extreme speed.²² Future gains in efficiency are expected to come from further optimization of LTPO technology, allowing rates to dip even lower, perhaps sub-$1$Hz for the Always-On Display, and from improvements in the power-to-performance ratio of the Display Driver IC itself, which remains a key area of energy loss, even more so than the pixels or the backplane in many modern display configurations.