Apple developers should start transitioning their applications to support 64-bit. With the release of macOS High Sierra 10.13.4, Apple will start warning users if they launch an app that doesn’t have 64-bit support.
According to the company, if a user sees this alert, it means that the application is not optimized for their system. All new apps submitted to the Mac App Store must have 64-bit support, and all app updates and existing apps must support this by June 2018.
“If you distribute your apps outside the Mac App Store, we highly recommend distributing 64-bit binaries to make sure your users can continue to run your apps on future versions of macOS,” Apple wrote in a statement.
Apple says 64-bit apps can dramatically improve the memory and performance of a system. “State-of-the-art technology is what makes a Mac a Mac. All modern Macs include powerful 64-bit processors, and macOS runs advanced 64-bit apps,” the company wrote. “The technologies that define today’s Mac experience—such as Metal graphics acceleration—work only with 64-bit apps. To ensure that the apps you purchase are as advanced as the Mac you run them on, all future Mac software will eventually be required to be 64-bit.”
Users may continue to use 32-bit apps on their Macs today, and it will have no adverse effects on their data or computer, the company explained. The final transition dates have not been revealed yet.