A move to 64-bit is designed to allow iPhones and iPads to run programs more efficiently – but it will render older apps obsolete.
Alongside the iPhone 8 and iPhone X, Apple is beginning to roll out the newest version of its operating system, iOS 11, on Tuesday.
The software is freely available for Apple customers and will arrive with a range of improvements on the previous operating system.
But iOS 11 has the potential to leave iPhone and iPad users unable to access their favourite apps if they are old and no longer supported by developers.
The new operating system is going to be restricted to running apps written in 64-bit code, meaning many older apps written in 32-bit code will stop working for users after they update their systems.
Users can avoid being locked out of their favourite apps by making sure they are updated before upgrading their operating system, which is optional.
Apple has consistently warned about its intentions to get rid of 32-bit apps, and users have been presented with pop-ups telling them about the slowdown for a long time.
Back when Apple released iOS 9, it explained that 32-bit apps could cause iPhones and iPads to perform a little worse than usual.
:: What’s the difference between 32-bit and 64-bit?
The numbers 32 and 64 refer to the amount of information that a processor can handle.
While a 64-bit processor may seem as if it could only cope with twice as much information as a 32-bit processor, it is actually capable of handling magnitudes more.
A bit – a single unit of information – has two values, and can be either a 1 or a 0.
Two to the power of 32 is just under 4.3 billion, but two to the power of 64 is more than 18 trillion.
Theoretically, the number of values that a 64-bit processor could address is thousands of times larger than that of a 32-bit processor.
