ScaleFlux is one of the few storage companies designing its own SSD controllers entirely in-house, giving it tight control over performance, latency, and efficiency. The CSD5320 marks the company's entry into the PCIe 5.0 enterprise SSD market, featuring the proprietary FX5016 controller paired with SanDisk BiCS8 218-layer NAND. The drive tested came in the E3.S form factor with 7.68 TB capacity.

What sets this SSD apart is its transparent hardware-based compression, which analyzes 4 KB data blocks and compresses them on the fly without any user intervention. The compression operates directly in hardware rather than firmware, adding only single-digit microseconds of latency to reads while writes remain fully pipelined. With a realistic 2:1 compression ratio, effective endurance jumps from 21,000 TBW to approximately 142,000 TBW—equivalent to over 3 DWPD typically reserved for premium enterprise drives. Random write IOPS also scales dramatically from 370K to 1M.

The CSD5320 delivers 13,000 MB/s sequential reads and 9,300 MB/s writes, with random reads hitting 3.1 million IOPS. Originally priced around $880, NAND demand has pushed current pricing to approximately $0.25 per GB—roughly $1,920 for the 7.68 TB model, though some sellers exceed $2,500. For workloads with compressible data, the compression effectively acts as additional over-provisioning, delivering enterprise-grade endurance in a seemingly standard 1 DWPD package.