People who purchased an iPhone 8, iPhone 8 Plus, or iPhone X may see their phone's performance slow down thanks to new software. Apple distributed iOS 12.1 earlier this week and with it new tools for managing battery life and performance. People who own these phones can use the system settings to choose top optimize speed or battery life. In December 2017, Apple admitted to slowing down older iPhones in order to prevent them from shutting down. The issue pertained to how lithium ion batteries lose capacity over time. Apple placed a priority on keeping the phone up and running over raw speed. Apple later introduced software allowing customers to choose between the two. This same software is now on the 2017 batch of iPhones from Apple. "Starting with iOS 12.1, iPhone 8, iPhone 8 Plus, and iPhone X include this feature, but performance management may be less noticeable due to their more advanced hardware and software design," said Apple on its support page. Apple had initially implied that its 2017 iPhones wouldn't need this software.