A cost/power efficient storage system with directly connected FPGA and SATA disks

Providing large storage on Multi-Access Edge (MEC) devices has various advantages: A large amount of bare data that cannot transfer to the cloud without anonymization can be kept easily. Preprocessing in the MEC devices is a hopeful approach for making "well-selected data"for training AI algorithms on the cloud. By distributing big data across numerous base stations, it is possible to prevent data loss during times of disaster. For such purpose, we propose the Trefoil storage subsystem supports cost and power-efficient stand-alone storage by connecting FPGA boards and up to 32 SATA Solid-State Drives (SSDs) directly. We introduced LiteX, an open-source FPGA system integration tool, to design the storage system. Various LiteX IP cores, including soft CPU cores(VexRISCv), memory controllers (LiteDRAM), and FPGA interconnect controllers (LiteICLink), are combined as well as the SATA controller(LiteSATA). We built an example evaluation system and evaluated a storage system's performance and power consumption with multiple SATA disks. Our evaluation results show that the designed SATA system can best use the SATA disk's maximum bandwidth, 569.1MB/sec for write operations and 523.8MB/sec for read operations. Striping data access with multiple disks demonstrates almost no overhead for a read operation, while a slight speed decrease of 4.24MB/sec per unit was observed for the write operation. Only 3W for the disk unit is needed during disk access. As an example application, a quantum computer simulation is briefly introduced.