The iPhone’s Low Power Mode is not a new feature. Introduced with iOS 9 back in 2015, it has been a staple for extending battery life in situations where users might spend extended periods without access to a charger. However, many new iPhone users often complain about their devices running slowly, unaware that Low Power Mode is activated. This article delves into how Low Power Mode affects iPhone performance and provides insights into its practical applications.

How Does the iPhone’s Low Power Mode Work?

Apple designed Low Power Mode to help users extend their iPhone’s battery life in situations where they know they will be away from a charger for extended periods. When activated, Low Power Mode reduces power consumption by turning off multiple software and hardware features together. Although iOS prompts users to enable Low Power Mode when the battery reaches 20 percent, the feature can be manually enabled at any time.

Apple describes the feature as follows:

Low Power Mode reduces the amount of power your iPhone or iPad uses when the battery gets low. When Low Power Mode is turned on, your iPhone or iPad will last longer before needing to be charged, but some features may take longer to update or complete. Also, some tasks may not work until Low Power Mode has been turned off or until you charge your iPhone or iPad to 80 percent or higher.

Users can check if Low Power Mode is activated by looking at the battery icon in the Status Bar – if it’s yellow, the device is in Low Power Mode.

But what exactly does Low Power Mode change on your iPhone? Apple provides an official list of changes:

• Turns off or reduces the use of 5G (depending on the iPhone model)
• Sets Auto-Lock to 30 seconds
• Reduces display brightness and limits the refresh rate to 60Hz on devices with ProMotion
• Turns off Always-On Display on compatible iPhones
• Reduces visual effects
• Pauses background activities (such as downloads, iCloud sync, backup, and email fetch)

Does It Slow Down Your iPhone? Yes

While Apple’s official list of changes does not mention performance, Low Power Mode also significantly slows down the device when activated. The chip inside your iPhone has multiple performance and efficiency cores. In typical usage, your iPhone can use all of the chip’s cores simultaneously, prioritizing the performance cores when you’re editing a video or playing a game. When Low Power Mode is on, the iPhone heavily reduces the use of the performance cores, relying mainly on the efficiency cores – which are slower but use much less power.

In a benchmark test used to score the performance of different devices, this is the score of the iPhone 16 Pro Max’s A18 Pro chip when Low Power Mode is off (the higher, the better):

• Single-core: 3,341
• Multi-core: 8,270

Now, the same test run with GeekBench 6 when Low Power Mode is on:

• Single-core: 1,384
• Multi-core: 4,093

Essentially, the device runs at about half its performance with this mode on. As a result, you’ll probably notice that your phone is slower depending on what tasks you’re doing. This may seem obvious to some, but many users are surprised to learn about this effect.

Wrap Up

Keeping Low Power Mode on all the time will make the battery last much longer, right? Well, that depends. Multiple tests show that Low Power Mode is more effective at reducing battery consumption in standby mode with less effect when you’re actively using the phone.

In that case, you should probably only use Low Power Mode when you really need it. It’s worth noting that Low Power Mode is also available on iPad, Mac, and Apple Watch.

As a practical example, consider a user who frequently travels for work and needs their iPhone to last through long flights and meetings. Activating Low Power Mode before a trip can ensure the device remains functional for essential tasks without draining the battery prematurely. However, for everyday use, it’s generally best to keep Low Power Mode off to maintain optimal performance.

For those who frequently engage in resource-intensive activities like gaming or video editing, disabling Low Power Mode is crucial. These activities require the full power of the iPhone’s performance cores, and any reduction in performance can significantly impact user experience. For instance, a gamer might notice lag or stuttering in gameplay, while a video editor might experience slower rendering times.

In summary, while Low Power Mode is a valuable tool for extending battery life in critical situations, it should be used judiciously to avoid compromising performance. Understanding its effects and knowing when to enable or disable it can help users optimize their iPhone’s performance and battery life effectively.