Linux patch shows that Loongson 3A6000 series processors will support simultaneous multithreading SMT technology

Loongson Technology previously revealed that the Loongson 3A6000 has been taped out, but it has only undergone preliminary testing. There is still a process of performance investigation, optimization and productization to follow, and it will take half a year to a year to complete the productization plan.

Since last month, Loongson engineers have been adapting Linux to run stably on its upcoming 3A6000 series processors.

Loongson recently released a new Linux patch, indicating that the Loongson 3A6000 processor will support simultaneous multithreading (SMT) technology. Similar to common Intel, AMD and POWER processors, SMT can double the number of logical cores, that is, 4 cores and 8 threads.

Simultaneous multithreading (SMT), also known as synchronous multithreading, is a technology that improves the overall efficiency of superscalar CPUs with hardware multithreading. Simultaneous multithreading allows multiple independent threads of execution to better utilize the resources provided by modern processor architectures.

According to the currently known information, the main frequency of Loongson 3A6000 is 2.5GHz, with a quad-core and dual DDR4-3200 memory channel design. The SPEC CPU2006 single-threaded fixed-point base score exceeds 40 points, the floating-point score exceeds 50 points, the multi-threaded fixed-point score exceeds 140 points, and the floating-point score exceeds 130 points.

Loongson Technology believes that the performance of 3A6000 is comparable to AMD's 7nm Zen 2, which is equivalent to the level of Intel's 10th-generation Core.

In addition, the official found in the test that there is a certain gap between the Loongson GCC compiler and the X86 GCC compiler. The number of dynamic instructions of many applications is significantly higher than that of X86. It is estimated that the running score will be further improved after compilation optimization.

Loongson emphasized that Loongson will continue to increase its main frequency, but will not follow Intel's current technical route of sacrificing efficiency for frequency, and will strive to continuously reduce costs and power consumption at the 3GHz level.

It is worth mentioning that the next generation of Loongson 3A6000 will be 3B6000, which adopts a design of four large and four small eight cores and has a self-developed GPU built in. The large core strives to improve the performance by more than 20% through structural optimization, but the official believes that it is quite difficult.

Loongson will also develop 3A7000 or 3B7000 based on 3B6000 using more advanced technology. In the second half of the year, technical preparations for more advanced technology will be carried out (because Loongson insists on self-developed IP, it needs to customize PHY such as memory interface and PCIE interface, which will take about 1 year).