Do Loongson Technologies’ Quad-Core Processors Rival AMD’s 28nm CPUs?

January 06, 2020 by Cabe Atwell

Loongson’s 3A4000 and 3B000 processors were manufactured using ST’s 28nm FD-SOI process.

China-based chip maker Loongson Technologies (formerly known as Godson) has unveiled its new quad-core 3A4000 and 3B4000 processors.

Loongson states that their 3A4000 processor is targeted at the mainstream market, while the 3B4000 is headed for server operations. The company claims both CPUs are 100% made in China without any third-party outsourcing.


The 3A4000 and 3B000 processors come in an FCBGA-1211 package. Image used courtesy of Loongson Technologies

These new CPUs, which are manufactured using ST’s (PDF) 28nm FD-SOI process, are said to offer equivalent performance as AMD’s 28nm Excavator CPUs released in 2015. A closer look at these processors' key features (especially their on-chip security) can help us assess how they size up.


Improvements from the Last Generation

Both chips use the same (PDF) GS464V micro-architecture as the previous 3000 series and have been optimized for greater performance over the company’s last-gen offerings. According to Loongson, this optimization includes increased operating frequencies, support for virtualization, vector support, encryption/decryption, and added security mechanisms.

Loongson’s press release also explains that “The 3A4000 / 3B4000 uses Loongson’s latest-generation processor core GS464V, clocked at 1.8GHz-2.0GHz. SPEC CPU2006 fixed-point and floating-point single-core scores are more than 20 points, which is more than double the previous generation products.”


Diagram of 3A4000

Diagram of 3A4000. Image used courtesy of (PDF) Loongson Technologies 

The 3B4000 server version can utilize ECC (Error-Correcting Code) memory and can utilize an 8-way configuration to increase performance 4-times over Loongson’s previous generation of processors, which are limited at 2-way deployment only.


Key Features

Both the (PDF) 3A4000 and 3B4000 are quad-core processors and feature 64Kb of L1 cache, 256Kb of L2 cache, and 8Mb of L3.

Both processors also pack:

  • Two 72-bit DDR4-2400 controllers (supports EEC check)
  • Two 16-bit HyperTransport 3.0 controllers with 2/4/8 way Multiprocessor Data Consistent Interconnect (CC-NUMA) support
  • SPI, UART, I2C, and 16 GPIO interfaces

Processor speeds range from 1.5GHz to 2.0GHz and consume 30- to 50-watts depending on the frequencies.

Loongson has already laid a roadmap for this year’s rollout of the processors in the Chinese market, which includes a quad-core 3A4000 CPU and a 16-core 3B4000 CPU. These CPUs use an up-to-date 12nm manufacturing process and are expected to come clocked to 2.5GHz later this year.   


On-chip Security

On the security side, both the 3A4000 and 3B4000 offer on-chip protection from the Meltdown and Spectre security vulnerabilities that plagued Intel’s CPUs early last year. The processors also feature native encryption/decryption algorithms, including MD5, AES, and SHA.


3A4000 and 3B4000 processors

Both the 3A4000 and 3B4000 processors are outfitted with four cores, 8Mb of L3 cache, and are clocked at 1.5GHz to 2.0GHz. Image used courtesy of Loongson Technologies


They are outfitted with dedicated, trusted security modules, “national secret algorithms,” and support access control mechanisms such as “Shadow Attacks.” All safety control mechanisms are integrated within the processor cores to achieve intrinsic safety. 



When it comes to quad-core processors, what features rank most important to you? Frequency? Support for virtualization? Vector support? Encryption/decryption? Share your thoughts in the comments below.