The Western Digital WD Gold WD4004FRYZ is a 3.5-inch internal hard drive designed for demanding data center and enterprise environments. With a capacity of 4 TB and a rotational speed of 7200 RPM, it handles heavy workloads efficiently, supporting a workload rate of up to 550 TB per year. The drive utilizes a SATA 6 Gb/s interface and a 256 MB cache to achieve a maximum sustained transfer rate of 267 MB/s, ensuring that data moves quickly during intensive operations. Reliability is central to its design, featuring Conventional Magnetic Recording (CMR) and HelioSeal technology to protect the internal components. These engineering choices contribute to a mean time between failures of 2.5 million hours, making it a dependable choice for those running servers or high-availability systems on Windows, Linux, or macOS. The unit weighs approximately 750 g and fits standard drive bays with dimensions of 147mm x 101.6mm x 26.1mm, while OptiNAND technology helps optimize performance and reliability for professional storage needs.