Intel® Xeon® D-1541 8-core 2.1 GHz. Built-in dual-port 10GbE. 16 GB ECC DDR4 Up to 64 GB. Up to 40 drive bays with RX1217(RP). Securing your business assets. The 16-bay RS4021xs+ provides solid data security and lightening-fast performance with over 234K 4K random read Iops and 6,258 MB/s sequential read throughput1. Together with its 8-core processor, ECC memory, advanced snapshot technology, and built-in 10GbE connectivity, the RS4021xs+ can support large multi-user environments while handling data-intensive workloads. Engineered for service continuity. The RS4021xs+ ensures mission-critical data is always available, enabling businesses to deliver the best results, even in the face of disaster. Redundant power. Dual PSUs provide protection against a PSU failure or accidental cord removal while hot-swappable fans can be replaced without powering down the system. Maximize service availability. Synology High Availability (SHA) pairs two identical units together creating an active-passive cluster with minute-level failover. Next-generation file system. Btrfs prevents data corruption and reduces maintenance overheads with advanced storage technologies and optimized snapshots.