The ThinkSystem S4520 Read Intensive SATA SSDs use 144-layer Intel 3D NAND TLC Flash Memory technology with a 6Gbps SATA interface to provide an affordable solution with industry leading performance. Compared with the S4510 series, these new Read Intensive (Entry) drives offer improved endurance. The S4520 SSDs are optimized for read-intensive applications such as boot, web servers, lower data rate operational databases and analytics.