I believe that many friends have purchased the latest generation of CPU platform Android machines. The CPU of this generation of Android machines has undergone drastic changes, while maintaining the large, medium, and small core architecture, the microarchitecture of large cores and small cores has been greatly changed. The microarchitecture evolution of the small core should be long-awaited, the ancestral Cortex-A55 is finally retired, and it is reasonable to say that the new Cortex-A510 should bring better energy efficiency. But some people have found that this generation of Android machines seems to consume more power, why is this? Today, let's start with the architecture of the new generation of ARM processors, and briefly talk about the power consumption problem caused by the 64-bit popularity lag of Android applications.
(Why does the new generation of ARMv9 processors consume more power?) ）
New ARM processors consume even more power?
The Qualcomm Snapdragon 8gen1 processor used in the latest generation of Android machines currently on the market, as well as the upcoming MediaTek Tianji 9000 processor, are the latest design products based on the ARMv9 architecture. They all have a common feature, which is that the large-core and small-core microarchitecture mentioned at the beginning of the article has been overhauled, with the large core using the Cortex-X2 microarchitecture and the small core using the Cortex-A510 microarchitecture.
(The new processor's small core is the redesigned Cortex-A510, which could theoretically lead to greater energy efficiency.)
Both the Cortex-X2 and the Cortex-A510 have in common that they no longer support 32-bit, and if android machines are to run 32-bit applications, they must be run in the Cortex-A710, which has only minor microarchitecture adjustments. As a result, in some scenarios, it is possible to cause additional energy consumption.
In the ideal case, when the Android machine is in standby or low load, the application mainly runs on the small core, and the energy efficiency ratio of the small core is the best, so that the power saving effect can be achieved; but now, if the App is 32-bit, in the new ARM processor, it can only be run by the medium core, and the energy efficiency advantage of the small core can only be dry eyes, and the additional power consumption will appear.
(When running a 32-bit Android app, the processor can actually only work in The Performance condition, not in the power-saving Eficiency condition.)
In other words, in Android machines using a new generation of CPUs, if you run a 32-bit app, you can't achieve the ideal energy efficiency ratio. This problem, which has nothing to do with the chip process and the system, is indeed caused by the mismatch between the Android ecosystem and the new processor architecture.
Only 64-bit Android apps can run on the small core of the new ARM processor, so that the new ARM processor can play the energy efficiency it deserves. Therefore, when to popularize 64-bit Android apps has become the answer to the question of when the new generation of ARM processors will be able to save more power.
Android apps still not popular with 64-bit?
In the current Android ecosystem, 32-bit applications still exist in large quantities, and these applications are not lacking in common installation necessities, such as Bilibili, Baidu network disk, iQiyi and so on. Is this normal? From a technical point of view, it seems very undeserved.
(Apps like Bilibili that have updated the Target API to Android 11 are still only 32-bit.)
Since THE BEGINNING OF ARMv8, THE CPU OF THE ANDROID CAMP HAS GENERALLY SUPPORTED 64-BIT, AND THE ANDROID SYSTEM ALSO SUPPORTS 64-BIT APPLICATIONS FROM THE SYSTEM LEVEL AFTER ANDROID 5.0. These two things, in fact, belong to the relatively ancient - BASED ARMv8 Snapdragon 810 and Android 5.0 appeared in 2014, the blink of an eye is almost ten years later, why android apps still stay in a large number of 32 bits?
We can compare the Apple camp. The iPhone 5S and iOS 7 in 2013 began to implement 64-bit, and more than a year later, 32-bit iOS applications have been difficult to trace. Compared with Apple's pace, the Android camp can be described as a difficult step.
(Compared with the Android camp, Apple's iOS implementation of 64-bit is much smoother)
Why is it so difficult for Android to implement 64? This is very much related to the actual situation of the Android ecosystem. Although after ARMv8, the CPU of the Android camp added 64-bit support, but still retained 32-bit compatibility. Even the previous generation of ARM v8.2 processors still consumes additional transistors to be compatible with 32-bit apps. At the same time, the Android system has always been compatible with 32-bit apps, and there is no urgent need for apps to switch to 64-bit. All of this consideration is largely based on the compatibility of older devices.
When Android first introduced 64-bit, there were still a large number of devices running old CPUs and older Android systems on the market. The secret of Android's attack on the market lies in openness and compatibility, if the 32-bit one-size-fits-all, then the Android camp will inevitably usher in a split. In fact, open systems have such problems, such as the Windows ecosystem in order to maintain backward compatibility, to this day still provide excellent compatibility with 32-bit applications, which is the same as Android.
Of course, unlike Windows, Android doesn't have to take on too many productivity tasks. Nearly a decade after the first 64-bit introduction, Android has indeed reached the time to completely abandon the 32-bit package.
What benefits can Android abandonment bring to 32-bit compatibility? First, the CPU can save the use of 32-bit compatible transistors, which is particularly valuable for chips that are scarce; second, the app can have better memory utilization, which is crucial for the growing application game; and second, the app can also make more efficient use of the CPU's registers, bringing greater efficiency.
Today, when Android apps are becoming more and more complex and Moore's Law is becoming more and more invalid, the time has indeed come to abandon the historical package and fully embrace the 64th. Although there are still a large number of 32-bit apps in the Android ecosystem, we can also see many efforts to popularize 64-bit. For example, Google requires that apps published on Google Play must support 64-bit from August 1, 2019. Because of this, the foreign Android ecology for the popularity of 64 bits is better than the domestic, this Time the Android CPU platform replacement, the domestic Android machine power consumption problem is more obvious than abroad.
(The Google Play Store banned 32-bit apps from listing more than two years ago, and the domestic Android ecosystem lags behind)
For example, domestic Android distribution channels have also begun to require apps to support 64-bit. The OPPO store has previously stipulated that after the end of December 2021, newly released apps must support 64-bit; while the Xiaomi store provides a one-click ability to replace 32-bit apps with 64-bit, if the 32-bit app installed on the phone has a 64-bit version in the store, it can be updated with one click.
At the same time, many domestic apps have also been updated to 64-bit in the near future, such as WeChat, QQ, 12306 and so on. It is believed that in the near future, the domestic Android App will soon be widely popularized by 64 bits, and the new generation of Android machines will also play its due energy efficiency.
summary
There is no doubt that compared with Apple, Android's 64-bit popularization process is backward, and the Android camp does not have the absolute monopoly of application distribution channels like Apple, which is also the price that Android needs to pay to take off through the wind of openness. Fortunately, all parties in the Android camp have realized the importance of popularizing 64-bit, will the next generation of Android CPUs further abandon support for 32-bit? Let's wait and see.