Xiaomi's 3nm Smartphone SoC Successfully Taped Out!

On October 20, Beijing News reported that Xiaomi has successfully completed the tape-out of its first smartphone system-on-chip (SoC) using a 3nm process. This development marks a significant breakthrough for Xiaomi in its efforts to develop in-house mobile SoCs.

Earlier in August, Chip News announced that Xiaomi's next-generation SoC is expected to launch in the first half of 2025, with predictions suggesting it would utilize TSMC's N4P process technology, potentially matching the performance of Qualcomm's Snapdragon 8 Gen 2.

Recent updates indicate that Xiaomi's new SoC will be even more ambitious, adopting the latest 3nm process technology, likely based on TSMC's current flagship N3E process. Industry insights suggest that the SoC features Arm's latest Cortex-X925 ultra-large core CPU.

According to Arm's specifications, the Cortex-X925 is their most powerful CPU core to date, based on the new Armv9.2 instruction set. It supports SVE and SVE2 instructions, delivering a 36% improvement in single-threaded performance compared to flagship CPU cores from 2023.

To manage the impressive performance of the Cortex-X925 while controlling power consumption, MediaTek's Dimensity 9400 features only one Cortex-X925 core in its design. Speculatively, Xiaomi's SoC might also include a configuration of one Cortex-X925 ultra-large core, three Cortex-X4 large cores, and four Cortex-520 cores.

Given the inclusion of the Cortex-X925, it stands to reason that the GPU would utilize Arm's latest flagship GPU, the Immortalis-G925. Arm claims that the Immortalis-G925 enhances frame rates through support for fragment pre-processing and dual-tiled processing unit throughput, enabling longer gameplay sessions with better performance. This GPU offers a 37% improvement in graphical performance over the previous Immortalis-G720, while reducing power consumption by 30%. It can sustain an average of 120 frames per second in a variety of popular mobile games and significantly enhances ray tracing capabilities for complex objects.

As for the 5G modem solution, Xiaomi may face challenges in developing this technology independently due to the extensive technical complexities and patent barriers involved. Even Apple has struggled for four to five years to establish its own modem. Therefore, Xiaomi is likely to opt for external 5G modem solutions from MediaTek or Unisoc.

In summary, if the speculations hold true, Xiaomi's 3nm SoC could achieve performance levels comparable to Qualcomm's Snapdragon 8 Gen 3 and MediaTek's Dimensity 9300, making it suitable for the company's mid-range flagship products in the coming year.