Mobile CPU Knowledge Literacy: Talk about mobile phone CPU architecture and principles (full

The CPU is the most complex, most expensive SOC (chip) on the phone, which is also the location of the brain in the cell phone, and is the decisive hardware for the performance of the mobile phone. The development of smartphones to today, the major mobile phone CPU manufacturers from the spring and autumn warring States gradually to the current four-country separation of the Times (Qualcomm, MTK, Samsung, apple a series). Of course, the largest CPU vendors are Intel, but Intel's main force is the x86 architecture of the processor, the main PC and server products. Our main character today is the mobile processor of the ARM architecture (mobile CPU).

First, let's look at the classification of the mobile phone CPU:

AP Application Processor:

The main part of the mobile phone's CPU, the mobile phone system operation and the operation of the app, rely on the AP application processor. For example, an Apple A9 processor refers to an AP.

BP Baseband Processor:

In fact, many players have only heard the baseband this thing, but do not know what this is. The baseband processor manages all wireless signals (except WiFi, Bluetooth, NFC, etc.), how many network modes a phone supports, and whether 4G or 3G is supported by the baseband section. BP's most famous is Qualcomm, in fact, Qualcomm is rich by the excellent BP baseband processor, not AP application processor.

Perhaps we have no impression of Qualcomm BP, here I would like to give you a few use Qualcomm BP mobile phone. IPhone4 to iphone6sp full range of mobile phones are using high-pass BP (these phones are my own disassembly, iphone3gs and so I am not sure if it is Qualcomm BP), as well as all the 3G version of the ipad, plus Samsung These years of the flagship is also used by BP, There are also a large number of mobile phone products using high-pass CPU are also using Qualcomm BP. So what is the position of Qualcomm in the field of BP I don't have to say.

CP Multimedia Accelerator:

In fact, each vendor has a different name for the CP, such as Apple called it coprocessor, Qualcomm 820 is called "Low power Island." The early CP is only used for simple tasks such as decoding video and processing audio.

However, the major manufacturers found that the performance of CP can be very high, so began to deal with more and more things. Now the CP has been able to handle virtual reality, augmented reality, image processing, HIFI,HDR, sensors and more.

Second, mobile phone CPU core number is really more the better?

From 2011 Nvidia released a dual-core mobile phone CPU began, mobile phone CPU nuclear war broke out, to the following 4-core, 8-core, 10-core. Even Intel has shown a 80-core processor prototype to the outside world, but so far there are no systems that can take advantage of the processor.

Here I can tell you very clearly that the more core number is definitely not a better representation. The best-performing processor for ARM architecture now is Apple's A9X (the processor used by IPad Pro), but A9X is just a dual-core CPU.

So why do some dual-core CPUs have better performance than the so-called 8-core CPUs? Because the size of the CPU logic part determines the number of CPU transistors (the white-gray part). Is the size of the Samsung Orion 7420 and Apple A9, we are not difficult to find the Apple A9 dual-core CPU logic components larger than the size of the Samsung 8 core, which means that the number of transistors A9 more than Samsung 7420. This makes the A9 much better than the 7420 performance.

So is it not good to say that multi-core?

Of course not, multi-core does a better job than multitasking and power. But do we really need 8 cores in a lot of times? Apple tells us that regardless of Android, the iOS dual core is sufficient anyway, which is very much related to the use of the iOS background processing mechanism (iOS will close the previous app after running a lot of apps).

But how many cores does it take to shut down the backstage Android? I think the Dragon 820 has told us that 4 cores are enough.

Third, the difference between ARM architecture and X86 Architecture:

ARM Architecture:

The ARM architecture uses a streamlined instruction set, which we can think of as a car that has always been synonymous with low power consumption.

X86 Architecture:

The X86 architecture uses a complex set of instructions, which we can think of as an aircraft that has always been synonymous with high performance.

The first is also because of the low power, so the mobile device, are used arm. But with the rapid development of the mobile side, the performance of the ARM architecture's processor is beginning to become more powerful.

So what's the difference between the CPU in the ARM architecture versus the CPU on the PC?

For example, a command came, to transport a cargo from Beijing to Shanghai, this time we will find that the plane must be faster than the car, but if another order is to bring a cargo from the street to the end of the street? At this time, the plane found that it is not likely to be basic, this time only to add a new instruction set (equivalent to re-production of a size suitable for the aircraft).

However, with the rapid development of mobile devices, the performance of ARM architecture has become more and more strong, the performance of ARM architecture over the X86 architecture is only a matter of time.

CPU inside of a lot of knowledge, today I only write the above three points, are more useful dry goods, hope to small white friends help. In fact, the decision to determine the CPU performance of mobile phones mainly by: core, main frequency, technology, GPU and other decisions, not a single aspect of strong performance is certain.

Mobile CPU Knowledge Literacy: Talk about mobile phone CPU architecture and principles (full