iPhone 5s is one of the most meaningful models in Apple's history. Not only because it first released Touch ID and iOS 7, but more importantly, the A7 processor made it the world's first mobile phone with a 64-bit architecture.
Since then, the Android mobile phone camp has also begun to use 64-bit architecture chips, and has gradually become the mainstream of the industry.
Behind the 64-bit architecture processor, there is a big brother named ARM who provides relevant technical support for mobile phone manufacturers. According to data, more than 95% of smartphones and tablets in the world are using ARM architecture.
Just recently, Big Brother ARM announced a big event: Starting from 2023, all mobile phones using its architecture will have a 64-bit CPU core and no 32-bit compatibility mode.
Simply put, 32-bit will be abandoned by smartphones and tablets, and the 64-bit era has come.
Why do we need 64-bit
In a smart phone, every photo, every file, and even every operation of yours is a string of numbers to the processor.
The processor stores these numbers in binary form, and the space allocated for them is "bit" as the smallest unit. In binary, a "bit" has two states, 0 and 1.
▲ Picture from: servicenowthink
This is a topic that is not easy to speak and understand. Let's make a less precise analogy first.
Assuming you are a computing terminal and a 32-bit CPU, you have 32 hands (registers), and each hand has 32 fingers (numbers that can be stored in the register). A 64-bit CPU means that you have 64 hands, and each hand has 64 fingers.
It is self-evident under which circumstances count more. 64-bit is a huge improvement over 32-bit.
▲Picture from: worldtechpedia
In the world of processors, a 32-bit architecture can access 2 to the 32th power of memory addresses, that is, 4GB of RAM or physical memory. The 64-bit architecture can access 2 to the 64th power of memory addresses, and theoretically supports 16TB of memory.
If the computing terminal has 8GB of RAM but is equipped with a 32-bit processor, it means that about 4GB of RAM is in an inaccessible state and wasted.
With the development of the software ecosystem, 4GB RAM can no longer meet the needs of some large-scale software. So processors and systems are moving towards 64-bit.
▲ Picture from: gearnews
As mentioned above, the vast majority of smartphones and tablets on the market are using ARM-based processors. The ARM architecture we often refer to mostly refers to the architecture of the ARM instruction set, which is the most important part of a processor structure.
For example, Qualcomm Snapdragon 888 uses one Cortex-X1, three Cortex-A78 cores and four Cortex-A55 cores. These cores all use the ARMv8 series instruction set architecture.
When did ARM embrace 64-bit? The clock can be dialed back to the winter of 2011.
At that time, ARM released the 8th edition instruction set architecture ARMv8, introducing the 64-bit instruction set for the first time. However, it does not only support 64-bit systems or applications, but is also backward compatible with previous 32-bit architectures.
▲The features of ARMv8 compared to the previous generation. Picture from: ARM
Most Cortex-A processors from Cortex-53 to Cortex-A75 support both 32-bit and 64-bit modes. Therefore, for consumers, there is no special feeling. Both 32-bit and 64-bit applications can be used normally.
Until some time ago, the 9th edition of the instruction set architecture ARMv9 was released, bringing three CPUs based on the new architecture: ARM Cortex-X2, Cortex-A710 and Cortex-A510.
▲ Three new CPUs. Picture from: ARM
Among these three CPUs, ARM Cortex-X2 and Cortex-A510 only support 64-bit operating systems and applications, and are no longer backward compatible. Only Cortex-A710 still retains support for 32-bit applications.
ARM subsequently announced that from 2023, all of its cores will stop supporting 32-bit operating systems and applications.
What does this mean? Cortex-A710 is likely to be the last CPU to support 32-bit applications, and 32-bit should completely say goodbye to mobile terminals.
▲Picture from: infoworld
The foundation of the 64-bit ecology is the operating system
On Windows computers, when we download software from the web, there are often 32-bit and 64-bit options. Generally speaking, 32-bit systems install 32-bit software, and 64-bit systems install 64-bit software.
For platform compatibility considerations, 64-bit systems can also install 32-bit software. In order to reduce the workload, some developers only provide 32-bit software.
▲ Picture from: MJ Tube
For "small and beautiful" software, 32-bit is indeed harmless, after all, it does not require much memory. However, 64-bit is the more ideal choice for applications that are large in size and call resources.
However, the prerequisite for 64-bit applications to run is a 64-bit system. We know that Windows has provided a 64-bit version a long time ago. Game consoles are earlier, even N64 in 1996.
▲Have you played N64? Picture from: bitlounger
So when did Android and iOS systems turn to 64-bit?
Let's look at Android first. In 2014, Android 5.0 (Lollipop) was released, which was the first fully compatible 64-bit version of Android.
After the release of iPhone 5s in the fall of 2013, iOS began to support 64-bit in both hardware and software. macOS is a bit earlier, the 10.7 Lion version in 2011, has entered the 64-bit era.
Android and Apple users don’t have to worry
In order to prevent consumers from being significantly affected when they fully transition into the 64-bit era, various systems have begun to plan the layout of the software ecosystem in the past few years.
For example, Android previously announced that since August 2019, all apps in Google Play need to support 64-bit. From August 1, 2021, Google Play on 64-bit devices will no longer provide 32-bit versions of apps.
Wechat, which we are familiar with, officially released the download link of the 64-bit version at the end of November 2019. It and Taobao have also become the first batch of domestic Android applications to embrace 64-bit.
▲ Android promotes 64-bit process table
In April of this year, Xiaomi App Store, OPPO Software Store, Vivo App Store, Tencent App Store, and Baidu Mobile Assistant also announced that in the future, applications that log on to the App Store must support the 64-bit ARM architecture in an orderly manner.
According to requirements, before the end of this year, all applications and games need to upload APKs with 64-bit builds as planned. Before the end of August 2022, all mobile Android programs in the Chinese market must be 64-bit universal.
▲ Picture from: xicom
Apple's attitude towards 64-bit is tougher than Android.
As early as February 2015, Apple announced that all iOS applications must support 64-bit. In 2017, Apple announced that iOS 11 will no longer support 32-bit applications.
▲ iOS 11 cannot run 32-bit old applications. Picture from: Qooah
This means that iOS has since completely abandoned 32-bit, and A11 and newer processors only support 64-bit applications.
Apple has the same strict requirements for macOS. Starting in 2018, all applications submitted to the Mac App Store must support 64-bit.
The macOS 10.15 Catalina, released in 2019, completely gave up support for 32-bit applications.
▲MacOS 10.15 Catalina cannot run 32-bit old applications. Picture from: pcmag
So for consumers, ARM will completely abandon 32-bit compatibility at this node in 2023 and will not have any obvious feelings. Because of the software ecology of each system, an orderly transition to 64-bit has been made for many years.
We have never heard of any major problems in the transition process. This timetable is more of a string for developers.
In the 64-bit world, Windows is also very greedy
Watching Android, iOS, macOS and other systems drifting away on the 64-bit road, Windows is envious of it.
Compared with mobile systems, Windows has too much historical baggage.
Even if it was a long time ago, Microsoft introduced 64-bit Windows. Nowadays, new computers generally have RAM above 4GB, and all pre-installed 64-bit systems. But the problem is that its software ecosystem cannot keep up with the hardware.
▲Windows 11 even supports Office 7.0 in ancient times. Picture from: Zhihu Answer Master XylonJack
It's not that developers are unwilling to do it, but that the penetration rate of 64-bit Windows is somewhat difficult to describe. Some enterprise-level users are even using 16-bit software, and can only install 32-bit operating systems for backward compatibility with 16-bit.
In addition, factors such as debugging and testing tools, third-party auxiliary plug-ins, and programmers' personal capabilities are all stumbling blocks to the full evolution of Windows toward 64-bit.
So, when will Windows meet Android, iOS, macOS and other systems in the 64-bit world? No one can know. Perhaps, Microsoft itself does not know.
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