Alibaba's Xuantie C910: Ambitious RISC-V Core, Short on Fundamentals

Alibaba's T-HEAD division has released the Xuantie C910, a high-performance RISC-V core aiming to reduce reliance on foreign chips and provide cost-effective solutions for IoT and edge computing. This deep dive analyzes C910's architecture, including its out-of-order execution engine, branch predictor, and cache system, revealing performance characteristics through testing. While excelling in vector extensions and unaligned access handling, C910 suffers from an imbalanced out-of-order engine with insufficient scheduler and register file capacity relative to its ROB size. Its weak cache subsystem further limits performance. Despite ambition, C910 needs improvement in balancing core architecture and memory subsystem.