This research provides the first comprehensive evaluation of CXL memory-expansion cards with production hardware, addressing key questions about performance characteristics and practical use cases.

• Performance of three CXL memory expansion cards exhibits 2-5× higher latency than local DRAM
• Memory bandwidth interleaving can significantly impact application performance with CXL
• CXL memory shows promise for memory capacity expansion applications despite latency challenges
• System architecture decisions around tiering and interleaving are crucial for optimal CXL implementation

This research matters for engineers and system architects designing next-generation memory solutions for data centers and large-scale applications where DRAM capacity limitations are a constraint.

Exploring and Evaluating Real-world CXL: Use Cases and System Adoption