Are Homemade CPUs Alibaba’s Bid For Independence?

China has taken another step toward semiconductor independence with Alibaba announcing the design of a 5-nanometer technology server chip that is based on Arm Ltd.'s latest instruction set architecture.

But, impressive as that feat is, an even more significant chip design development by the Chinese tech giant may be making available the source code to a RISC-V CPU core its own engineers designed. This means other companies can use it in their own processor designs-and escape architecture license fees. (The company made both announcements at its annual cloud convention in its home city of Hangzhou last month.)

The Chinese government is funding a lot of startups that are designing a variety of chips. The number of newly registered Chinese chip-related companies more than tripled in the first five months of 2021 from the same period a year ago. And the biggest Chinese technology companies like Alibaba, Baidu, and Huawei are developing their own chips rather than banking on those from Intel, Nvidia, and other United States-based companies.

"These flagship technology companies like Alibaba can help jumpstart the semiconductor industry by building very advanced chips," said Linley Gwennap, a semiconductor consultant.

China is intent on developing semiconductor independence, both in design and manufacture of state-of-the-art chips. The urgency for doing so has been helped along by U.S. sanctions against the Chinese telecommunications giant Huawei, which have cut the company off from foreign-built chips. The sanctions extend to any Huawei suppliers that use U.S. parts or technology.

The United States, alarmed at China's campaign to bring Taiwan under its control, has also begun an ambitious program to 'reshore' its semiconductor manufacturing after allowing much of it to migrate to Taiwan. Around 80 percent of the world's semiconductor production capacity is in Asia, and nearly all the most advanced logic chip production is in Taiwan. No Chinese semiconductor foundry has yet achieved the 5-nanometer processing needed to make Alibaba's new ARM-based chip, so it is still beholden to Taiwan for manufacturing.

But the implications of Alibaba's general choice of Arm and RISC-V instruction set architectures is perhaps more consequential for the long term. An instruction set architecture, or ISA, is the language in which software talks to hardware, and thus determines the kind of software that can run on a particular chip. Most servers use CPUs based on Intel's x86 instruction set architecture. But UK-based Arm, which licenses its instruction set architecture to chip designers, has been gaining a foothold in this market.

The RISC-V instruction set architecture has even fewer strings attached. RISC-V, which refers to the fifth generation of an open-source reduced instruction set computer architecture created by U.S.-based researchers, is free and therefore sheltered from geopolitical crosswinds.

China has two industry groups that promote RISC-V: The China Open Instruction Ecosystem Alliance and the China RISC-V Industry Consortium. This past June, China hosted the fourth annual RISC-V summit, bringing together industry, academia, and government to talk about the future of the architecture.

In the wake of the U.S. sanctions, which also cut Huawei off from using Google's Android operating system, Huawei released its first RISC-V development platform to help engineers use its own Harmony operating system for smartphones, IoT gadgets, and other so-called edge devices. Unable to buy Intel chips because of the sanctions, Huawei most recently sold its x86 server unit to a company owned by China's Henan province.

Alibaba introduced its first RISC-V processor in 2019, hailed as the most advanced RISC-V chip at the time. From the beginning, the company indicated that it intended to open the CPU's source code-the hardware description language that describes the structure and behavior of the CPU core's electronic circuits. It has now done so... with little fanfare.

"If Intel made the same announcement about the design of an x86 instruction set microprocessor, that would be seen a big deal," noted David Patterson, one of the creators of RISC-V.

RISC-V is gradually gaining on Arm and Intel as more and more chip and software vendors adopt the architecture. Patterson notes that all NVIDIA GPUs use RISC-V, Samsung phones use RISC-V and most open-source tools work for RISC-V. "RISC-V shipments are in the billions," he said, adding that Alibaba alone has shipped more than a billion cores using RISC-V. Meanwhile, there are already several other open-source RISC-V cores available on the Internet.

With RISC-V processors for lower-power tasks and custom Arm server CPUs for general computing, Alibaba now has the full range of computing infrastructure covered. Its Yitian 710 server system on a chip (SoC), manufactured by Taiwan's TSMC, will have a total of 128 Arm-based cores, with 60 billion integrated transistors and a top clock speed of 3.2GHz. Alibaba said it is the first server processor compatible with the latest Armv9 architecture.

Alibaba said the SoC achieved a score of 440 in SPECint2017 (a standard benchmark for measuring CPU integer processing power), surpassing that of the current state-of-the-art Arm server processor based on Armv8 by 20 percent in performance and 50 percent in energy efficiency.

The company also announced the development of proprietary servers, under the brand name Panjiu, developed for the next-generation of cloud-native infrastructure. By separating computing from storage, the servers are optimized for both general-purpose and specialized AI computing, as well as high-performance storage.

Meanwhile, by opening the source code of its RISC-V XuanTie series IP cores, developers will be able to build prototype chips of their own, customized for different IoT applications. Alibaba is also opening up XuanTie-related software stacks, which support multiple operating systems, including Linux, Android, RTOS and Alibaba's own AliOS. The company vowed to provide more services and support for RISC-V development tools, software development kits, and customized cores in the future.

Consultant Gwennap suggests that Alibaba's Arm and RISC-V efforts are experiments more than commercial endeavors, noting that Alibaba is still using x86 Intel chips for the vast majority of its internal use. "These companies are talking a lot about having an alternative to Intel," Gwennap said. "But when it comes down to it, they're not willing to eat their own dog food."

Alibaba's new Arm-based server chip will be used in Alibaba datacenters to provide cloud services to customers.. The company will continue to offer Intel-based services, so it's up to customers to choose Arm over x86-based chips. When Amazon did something similar a few years ago, there was little uptake for the Arm-based chips.

But true semiconductor independence will require China to develop its own extreme ultraviolet lithography machines, required to etch microscopic circuits on silicon. SMIC, China's main chip foundry, can't provide anything smaller than 14 nm. SMIC claims to have mastered the 3nm chip process in the lab and is trying to buy the EUV lithography machines necessary for production from ASML, the Dutch company that currently has a monopoly on the critical equipment. But the United States is intent on blocking the sale. (3 nm refers to the next reduction in minimum semiconductor feature size and tighter spacing to allow an increase in transistor density, but does not refer to the actual size of transistor gates or other features on the processor.)

The Chinese Academy of Sciences has an EUV lithography research team and Tsinghua University has developed a new type of particle accelerator light source, which could be used for EUV lithography. But getting that technology out of the lab and into a machine remains many years away.