The Synology RackStation RS4021xs+ is a powerful 16-bay 3U rackmount NAS solution designed for enterprise environments requiring high throughput and data integrity. Powered by a 2.1 GHz Intel Xeon D-1541 eight-core processor with 16GB DDR4 ECC memory (expandable to 64GB), this system delivers exceptional performance with up to 234,698 4K random read IOPS and 6258 MB/s sequential read speeds for demanding virtualization, mail, and surveillance workloads. Featuring dual built-in 10GbE RJ45 ports, four Gigabit Ethernet ports, and dual redundant power supplies for maximum uptime, the RS4021xs+ supports 3.5" and 2.5" SATA drives with flexible RAID configurations (0, 1, 5, 6, 10, Basic, F1, JBOD) and AES-NI hardware encryption. Expandable to 40 drive bays using two optional RX1217/RX1217RP expansion units, with two PCIe Gen3 x8 slots for network upgrades and M.2 NVMe SSD cache acceleration. Running on Synology DiskStation Manager (DSM) with advanced Btrfs file system and snapshot technology, the RS4021xs+ provides enterprise-grade storage with Synology High Availability support, backed by a 5-year limited warranty.