Monday 10 March 2025
The quest for a faster and more efficient way to store data has been ongoing for decades, with scientists and engineers constantly pushing the boundaries of what is possible. One of the most promising approaches in recent years has been the development of CXL-based solid-state drives (SSDs), which offer a scalable and cost-effective solution for expanding memory capacity.
However, despite their potential, CXL-SSDs have faced significant performance challenges due to the long flash access latency and unpredictable events such as garbage collection in the SSD device. These issues can cause the host processor to stall, wasting valuable compute cycles and reducing overall system performance.
To address this problem, a team of researchers has developed SkyByte, an efficient CXL-SSD that employs a holistic approach to optimize data access and reduce latency. The solution involves co-designing the host operating system (OS) and SSD controller, allowing for opportunistic context switches upon detection of long access delays.
One key innovation is the use of adaptive page migration, which promotes hot pages in the CXL-SSD to the host memory, reducing the need for flash accesses and improving overall performance. Additionally, SkyByte architects the internal DRAM of the SSD controller into a cacheline-level write log and a page-level data cache, enabling data coalescing upon log cleaning to minimize I/O traffic to flash chips.
To evaluate the effectiveness of SkyByte, the researchers used a cycle-accurate simulator based on MacSim and SimpleSSD. They ran a range of benchmarks, including Rodinia, GAP, Splashv3, WHISPER, and DLRM, and found that SkyByte outperformed current CXL-based SSDs by 6.11 times, with average memory access time reduced by 23.08%.
The team also demonstrated the flexibility of their approach, using custom configurations to adapt to different workloads and scenarios. By allowing users to fine-tune various knobs, such as the promotion threshold for adaptive page migration, SkyByte can be optimized for specific use cases.
The potential implications of SkyByte are significant. With its ability to improve data access times and reduce latency, it could enable new applications and workflows that rely on fast and efficient storage. Moreover, its scalability and cost-effectiveness make it an attractive solution for a wide range of industries, from data analytics to artificial intelligence.
Cite this article: “SkyByte: A Holistic Approach to Optimizing Data Access in CXL-Based SSDs”, The Science Archive, 2025.
Cxl-Ssd, Solid-State Drive, Memory Capacity, Flash Access Latency, Garbage Collection, Ssd Controller, Adaptive Page Migration, Data Coalescing, I/O Traffic, Cycle-Accurate Simulator
