Loongson is one of the few Chinese CPU developers capable of creating competitive processors for client and server applications, and is facing significant tailwinds following its recent inclusion on the US Department of Commerce Entity List. . It’s a spot on the list that restricts access to technology from the US and doesn’t cut the ability to make chips overnight, but Digi Times Reports suggest that it could pose a major problem in the years to come.
Unlike some other Chinese companies that use the Western-controlled Arm and x86 instruction set architectures, Loongson’s CPUs rely on the company’s own LoongArch ISA, which is backward compatible with the MIPS architecture. As a result, it is impossible for the US government to block access to his Loongson’s latest CPU technology. However, Loongson uses US electronic design automation (EDA) software to develop processors, while his manufacturing partner SMIC uses US-origin wafer fab equipment.
Companies such as Ansys, Cadence and Synopsys, which control over 90% of China’s EDA market, must obtain an export license from the US Department of Commerce to sell or support EDA programs to Loongson. In addition, manufacturing Loongson’s chips using 14 nm and 12 nm class process technology also requires manufacturing partner SMIC to obtain other export licenses from the US DoC.
Earlier this year, the Chinese government was found to have restricted exports of Loongson’s latest CPUs based on the LoongArch microarchitecture, citing the technology’s strategic importance and national security concerns.
Given the historical use and positioning of Loongson’s processors today, it is unlikely that the US Department of Commerce will grant an export license for US-originated technology sold to Loongson. As a result, Loongson will ultimately not be able to develop new CPUs using his current EDA tools. Additionally, SMIC and other chip makers cannot legally manufacture processors for Loongson unless they are properly licensed.
Loongson’s proprietary LoongArch microarchitecture certainly enables processor evolution, but restrictions imposed by the US government restrict the development and manufacture of real CPUs.
For now, the company has quad-core 3A5000 processors and 16-core 3C5000 CPUs for client PCs and 32-core 3D5000 CPUs for servers, and will continue to ramp up production of these chips whenever possible. A design for the company’s 6000-series processors based on the next-generation LA664 core (which promises performance to rival AMD’s Zen 3) is probably ready, but Loongson’s access to advanced process technology is uncertain. It remains to be seen whether the company will even be able to commercialize its next-generation CPU family.
