Mobile phone manufacturers: 5nm will be adopted this year

     In the past 2020, 5nm processors were only installed in a few models such as Apple iPhone12 series, Huawei Mate40, vivo X60 released at the end of the year, and Xiaomi 11 (in pre-order status as of the deadline). In 2021, 5nm processors will be used in more 5G models. Whether it is Samsung, which recently launched its second 5nm processor and the first model Galaxy S21, IQOO7 confirmed to be equipped with Qualcomm Snapdragon 888, or OPPO, Meizu, Black Shark and more than a dozen OEM manufacturers that support Qualcomm Snapdragon 888 platform, they are all eager to try the 5nm process. What changes has 5G superimposed on 5nm brought to mobile phone processors, and how do major chip manufacturers compete in this field? With the collision of new technologies and new processes, what new challenges does mobile phone chip design face?

　　More and more players are joining the game

　　At CES 2021, Samsung released its flagship chip Exynos 2100, which is the fifth 5nm 5G processor after Kirin 9000, Apple A14, Samsung Exynos 1080 and Qualcomm Snapdragon 888.

　　Generally speaking, mobile phone chips can be divided into AP (application processor) and BP (baseband chip). For the new generation of flagship chips, major chip manufacturers emphasize both the performance improvement brought by 5nm to AP and the BP capabilities developed for 5G.

　　Improving the process is very expensive, so the improvement of the process must bring about an improvement in chip performance to be considered "worth the money". Intuitively speaking, from the number of transistors, the number of transistors in Kirin 9000 has reached 15.3 billion, which is 5 billion more than the Kirin 990 (5G version) which uses TSMC's 7nm enhanced process. The Apple A14 has 11.8 billion transistors built in, which is nearly 40% more than the 7nm chip. In terms of performance data, the improvement brought by the 5nm process is also obvious. Compared with the previous generation flagship chip, the overall CPU performance of Snapdragon 888 has increased by 25%, and the graphics rendering speed of the GPU has increased by 35% compared with the previous generation platform. The performance of the Exynos2100 processor has increased by 19% in single-core and 33% in multi-core compared with the previous generation, and the graphics performance has increased by 40% compared with the previous generation.

　　As the amount of data processed by mobile phones has increased exponentially and the data types have become more diverse, AI has become a necessary skill for high-end mobile phone processors, and AP has also moved from "CPU+GPU" to "CPU+GPU+NPU/AI engine". In terms of AI computing power support, the cores of Apple's NPU (neural network processor) have doubled, and the computing power has reached 11.8TOPS. The computing power of Snapdragon 888 and Exynos2100 has been increased to 26 TOPS. The new generation NPU equipped with Kirin 9000 adopts a dual large core + micro core NPU architecture, and its performance has increased by 100% compared to Kirin 990 (5G).

　　The emphasis on 5G capabilities is also a major feature of 5nm processors. Multi-mode and multi-band connectivity is the configuration that all manufacturers emphasize the most. It supports 5G and is backward compatible with 4G LTE (Long Term Evolution), supports SA (standalone networking)/NSA (non-standalone networking) dual networking, is compatible with FDD (frequency division duplex)/TDD (time division duplex), and has carrier aggregation, DSS, dual SIM and even multi-SIM card functions, which have become standard for all products. While 5G improves the user's outdoor experience, the products of various manufacturers also generally support Wifi6 functions and ensure users' indoor connections, shaping a new mobile experience in the 5G era.

　　It is also worth noting that Unisoc and MediaTek have successively launched 5G SoCs (system-on-chips) with a 6nm process, which is only "a thin line away" from chip products with a 5nm process. MediaTek released a new 5G processor Dimensity 1200 with a 6nm process on January 20. According to relevant reports, MediaTek's 5nm chip code-named "Dimensity 2000" has met the case opening needs of customers such as OPPO, vivo, and Honor, and is expected to be officially launched in the first quarter of 2022. In 2022, the market is expected to see more 5nm processor design players.

　　How to build differentiated competition

　　Chip design is an innovation-intensive, technology-intensive, and asset-light industry, so the competition for 5nm 5G chips can be described as a pinnacle battle among the world's top manufacturers.

　　Yao Jiayang, an analyst at TrendForce, told China Electronics News that 5G mobile phone processors can be divided into several elements, namely the combination of CPU, GPU, DSP (digital signal processing)/NPU/APU (accelerated processing unit), 5G Modem, ISP (image signal processing) and advanced processes.

　　Taking the CPU as an example, the Cortex-X1 and A78 CPUs have already appeared in the products of Qualcomm and Samsung, in order to improve the overall computing efficiency of the processor.

　　Taking 5G Modem as an example, we can see the difference in millimeter wave and sub-6GHz (frequency band) support. In terms of process, although both use 5nm process, TSMC and Samsung still have slight differences in basic factors such as yield, performance and power consumption, which also leads to differences between 5G mobile phone processors.

　　The research and development focus of each manufacturer can be seen from the CPU research and development model. Although several chip manufacturers have adopted the Arm architecture to develop CPUs, in order to better integrate software and hardware capabilities, Apple's A series processors are mostly self-developed based on Arm's instruction set, and single-core performance is more prominent. Snapdragon 888 has been redeveloped based on the Cortex core to create the Kryo 680 architecture to improve the overall performance and stability of the product. Most other manufacturers use the public version of the Arm core.

　　In addition to the single-core structure, each company's multi-core architecture is also different. Huawei, Samsung, and Qualcomm have a larger span in performance improvement.

　　Samsung's Snapdragon 888 and Exynos 2100 both use a 3-cluster 8-core architecture consisting of "Cortex-X1 super core + 3 A78 large cores + 4 A55 small cores". But even with the same structure, Samsung has done more radical in improving performance, increasing the main frequency of the super core to 2.9GHz, slightly higher than the 2.84GHz of the Snapdragon 888.

　　Kirin 9000 adopts a 3-cluster 8-core architecture consisting of "A77 large core + three A77 medium cores + four A55 small cores", and the A77 main frequency has reached 3.13GHz, making it one of the highest frequency mobile phone processors currently available.

　　Apple pays more attention to the balance between performance and energy efficiency, and adopts a 6-core architecture with 2 performance cores and 4 energy efficiency cores.

　　According to the data released by Apple on the improvement of A13 and A14 relative to A12, the CPU performance of A14 has increased by 16.7% and the GPU performance has increased by 8.3% compared to A13, which is not a big improvement. However, in terms of energy efficiency, especially the performance in low power mode, Apple still has an advantage. Li Nan, a former executive of Meizu Technology, said that Apple's low power mode can maximize the advantages of the 5nm process.

　　The same is true for GPUs. Apple and Qualcomm both use self-developed GPUs, while Huawei and Samsung use Mali G78, with Huawei using 24 cores and Samsung using 14 cores.

　　Judging from the GFXBench graphics benchmark test released by foreign media in December last year, the image processing scores of the iPhone 12 series equipped with Apple A14 are in the leading position in the industry, followed by Qualcomm reference test machine and Mate 40, both of which have improved in visual processing capabilities.

　　In terms of 5G, Huawei, Qualcomm, and Samsung have all launched and integrated their own baseband chips on SoC.

　　From the perspective of a large frequency band, Huawei's Balong 5000, Qualcomm's X60 and X55 plug-in to Apple A14, and Samsung's Exynos 5123 all have the ability to support Sub-6Hz and millimeter waves at the same time.

　　Balong 5000 performs particularly well in Sub-6Hz. By supporting 5GSA dual-carrier aggregation, the theoretical peak rate of Sub-6G downlink reaches 4.6Gbps, the theoretical peak rate of uplink reaches 2.5Gbps, and it supports 11 5G TDD and FDD frequency bands.

　　The X60 baseband integrated in the Snapdragon 888 can provide a millimeter-wave downlink peak rate of 7.5Gbps, leading the industry. The Apple A14 with an external Snapdragon X55 baseband also enjoys this treatment. Apple iPhone supports up to 20 main 5G frequency bands, and the Exynos5123's millimeter-wave downlink peak rate also reaches 7.35Gbps.

　　The threshold for R&D is getting higher and higher

　　At the 5nm stage, there are only two foundries that can manufacture chips, and even fewer can design high-end process chips. For flagship smartphone processors, which must use advanced process technology as soon as possible and also have 5G and AI capabilities, the design threshold is obviously high.

　　On the one hand, 5G baseband design is difficult. It needs to maintain good interoperability with the network side and the terminal side, implement communication technology standards, be verified in laboratory and field tests, and be backward compatible with 3G and 4G. On the other hand, advanced processes allow chips to integrate more components and corresponding functions, which increases the integration and complexity of chips. Therefore, the difficulty of processor design has increased, and expenditures on R&D, design tool upgrades, wafer purchases, etc. have also risen sharply.

　　"With the improvement of process technology, the amount of research and development investment in mobile phone processors is getting bigger and bigger. The huge amount of research and development funds requires a large number of products to support and share the research and development expenses. The smaller the process technology, the higher the transistor density, which increases the difficulty of design. The upgrade of EDA tools requires more research and development funds, and the research and development funds required by wafer foundries and the purchase price of wafers will also increase." said Yao Jiayang.