Overview Summary
The Synology RS4021xs+ is a powerful enterprise-grade rackmount NAS designed for businesses that demand high-speed data access, reliability, and scalability. With a robust Intel Xeon processor, 16GB ECC memory, and built-in 10GbE connectivity, it delivers exceptional performance for data-intensive environments such as virtualization, backup, and multi-user collaboration. Its 16-bay design allows for massive storage expansion, making it ideal for growing organisations in South Africa looking to centralise and protect critical data.
Built with service continuity in mind, the RS4021xs+ features redundant power supplies, advanced snapshot technology, and seamless scalability up to 40 drives. Whether you're managing backups, running virtual machines, or deploying a private cloud, this NAS offers dependable performance and security. Shop now to upgrade your business infrastructure with a reliable and scalable storage solution.
Performance tier: Enterprise
Uses: data backup, virtualization storage, file sharing, surveillance storage, private cloud, disaster recovery Overview
Enterprise Rack NAS Built for Performance and Reliability
The Synology RackStation RS4021xs+ is a high-capacity 16 bay rackmount NAS engineered for demanding business environments. Designed to handle data intensive workloads, it combines strong processing power with advanced data protection and scalable storage. With an Intel Xeon processor, ECC memory, and integrated 10GbE connectivity, this system supports multi user operations while maintaining consistent throughput and responsiveness.
Description
The RS4021xs+ delivers enterprise grade storage with a focus on uptime, scalability, and data integrity. It is ideal for organizations requiring reliable centralized storage, virtualization support, and advanced backup solutions. With built in redundancy, flexible expansion options, and powerful management tools through Synology DiskStation Manager, it enables businesses to secure data, streamline workflows, and maintain continuous service availability in critical environments.
Features
Designed for Continuous Operation
Business continuity is a core strength of the RS4021xs+. Dual power supplies reduce the risk of downtime from power issues, while hot swappable fans allow maintenance without interrupting operations. Synology High Availability enables clustering of two identical systems, ensuring automatic failover with minimal disruption.
The Btrfs file system enhances data protection by preventing corruption and enabling efficient snapshot management, reducing administrative overhead while improving reliability.
Flexible Expansion and Customisation
The system adapts to evolving business requirements through multiple upgrade paths. PCIe slots allow for network and storage enhancements, while SSD caching significantly improves IOPS performance. Storage capacity can be expanded up to 40 drives using compatible expansion units.
Key upgrade options include:
- Increased network throughput using 10GbE network interface cards
- SSD cache acceleration for faster read and write operations
- Seamless storage expansion with additional drive enclosures
Comprehensive Data Protection and Backup
Built in backup tools ensure data is always protected and recoverable. Hyper Backup supports multi destination backups including cloud services, remote servers, and other NAS systems, with deduplication and incremental transfers reducing resource usage.
Snapshot Replication provides near instant recovery with frequent point in time backups, minimizing downtime and ensuring business continuity in the event of data loss.
Optimised for Virtualisation Environments
The RS4021xs+ integrates with major virtualisation platforms, making it suitable for modern IT infrastructure. It supports VMware, Windows environments, and OpenStack, enabling efficient storage provisioning and faster data transfer through offloading technologies.
Surveillance and Remote Access Capabilities
This NAS can function as a centralised video management system, supporting up to 90 IP cameras. Intelligent monitoring features such as motion detection and anomaly alerts enhance security operations.
Remote access is available through web browsers, desktop applications, and mobile apps, ensuring data and surveillance feeds are accessible from anywhere.
Centralised Management and Productivity Tools
Running on Synology DiskStation Manager, the system provides a comprehensive suite of applications for file access, collaboration, and infrastructure control. Centralised management simplifies administration across multiple devices, while integrated tools support team collaboration and virtual machine deployment.
Core Hardware and Performance Details
- Part Number / SKU: CAS-NASBOX-RS4021XS+
- Processor: Intel Xeon D-1541, 8 core, 2.1 GHz base up to 2.7 GHz turbo
- Memory: 16 GB DDR4 ECC UDIMM preinstalled, expandable to 64 GB
- Drive Bays: 16 with support for SATA HDD and SSD
- Maximum Expansion: Up to 40 drives with expansion units
- Maximum Volume Size: Up to 200 TB with sufficient memory
- Network: 4 x 1GbE ports and 2 x 10GbE ports with failover and link aggregation
- Expansion Slots: 2 x PCIe Gen3 x8
- External Connectivity: 2 x USB 3.2 Gen 1 and 2 expansion ports
Physical and Operational Characteristics
- Form factor: 3U rackmount
- Dimensions: 132.3 mm x 482 mm x 656.5 mm
- Weight: 17.4 kg
- Cooling: Triple system fans with multiple speed modes
- Power: 800 W redundant power supply
- Operating temperature range: 0 to 35 degrees C
A Scalable Storage Solution for Growing Businesses
The Synology RackStation RS4021xs+ provides a balance of performance, scalability, and reliability. Whether deployed for file storage, backup, virtualisation, or surveillance, it delivers consistent results in enterprise environments where uptime and data integrity are critical. Its modular design ensures it can evolve alongside business needs while maintaining efficient and secure operations.
Specifications
| ©2026 Respective owners and brand holders. This table has been carefully researched and generated by ComXpert International CC (//www.comx-computers.co.za), however, errors and omissions may occur. Only references to South Africa apply. All products are sourced in South Africa from the official suppliers and the warranty is that of the local supplier. E&OE. This table and our site's content may be used on condition that this notice and link remains intact and unaltered. |
Specifications |
| Product Code | CAS-NASBOX-RS4021XS+ |
| CPU |
| CPU Model | Intel Xeon D-1541 |
| CPU Quantity | 1 |
| CPU Architecture | 64-bit |
| CPU Frequency | 8-core 2.1 (base) / 2.7 (turbo) GHz |
| Hardware Encryption Engine (AES-NI) | Yes |
| Memory |
| System Memory | 16 GB DDR4 ECC UDIMM |
| Memory Module Pre-installed | 16 GB (16 GB x 1) |
| Total Memory Slots | 4 |
| Maximum Memory Capacity | 64 GB (16 GB x 4) |
| Notes | Please select Synology memory modules for optimum compatibility and reliability. Synology will not provide complete product warranty or technical support if non-Synology memory modules are used for memory expansion. |
| For more information on the recommended memory configurations, visit here. |
| Synology reserves the right to replace memory modules with the same or higher frequency based on supplier's product life cycle status. Rest assured that the compatibility and stability have been strictly verified with the same benchmark to ensure identical performance. |
| Storage |
| Drive Bays | 16 |
| Maximum Drive Bays with Expansion Unit | 40 (RX1217/RX1217RP x 2) |
| Compatible Drive Type* (See all supported drives) | 3.5" SATA HDD |
| 2.5" SATA SSD |
| Maximum Single Volume Size | 200 TB (32 GB memory required) |
| 108 TB |
| Hot Swappable Drive | Yes |
| Notes | It is strongly recommended that you only install drives listed on your device's compatibility list. Storage pool and volume creation processes may fail when using unverified drives. Synology is unable to provide technical support for devices using unsupported components. |
| "Compatible drive type" indicates drives that have been tested to be compatible with Synology products. This term does not indicate the maximum connection speed of each drive bay. |
| Each internal volume (may consist of multiple drives) is expandable up to 108 TB (with memory less than 32 GB) or 200 TB (with memory equal to or greater than 32 GB). |
| External Ports |
| RJ-45 1GbE LAN Port | 4 (with Link Aggregation / Failover support) |
| RJ-45 10GbE LAN Port | 2 (with Link Aggregation / Failover support) |
| USB 3.2 Gen 1 Port | 2 |
| Expansion Port | 2 |
| Notes | The USB 3.0 standard was renamed to USB 3.2 Gen 1 by the USB Implementers Forum (USB-IF) in 2019. |
| PCIe |
| PCIe Expansion | 2 x Gen3 x8 slots (x8 link) |
| File System |
| Internal Drives | Btrfs |
| EXT4 |
| External Drives | Btrfs |
| EXT4 |
| EXT3 |
| FAT |
| NTFS |
| HFS+ |
| exFAT |
| Notes | exFAT Access is purchased separately in Package Center. |
| Appearance |
| Form Factor (RU) | 3U |
| Size (Height x Width x Depth) | 132.3 mm x 482 mm x 656.5 mm |
| Weight | 17.4 kg |
| Rack Installation Support | 4-post 19" rack (Synology Rail Kit - RKS1317) |
| Notes | The rail kit is sold separately |
| Others |
| System Fan | 80 mm x 80 mm x 3 pcs |
| Fan Speed Mode | Full-Speed Mode |
| Cool Mode |
| Quiet Mode |
| Easy Replacement System Fan | Yes |
| Power Recovery | Yes |
| Noise Level | 44.7 dB(A) |
| Scheduled Power On / Off | Yes |
| Wake on LAN / WAN | Yes |
| Power Supply Unit / Adapter | 800 W |
| Redundant Power Supply |
| AC Input Power Voltage | 100 V to 240 V AC |
| Power Frequency | 50/60 Hz, Single Phase |
| Power Consumption | 145.79 W (Access) |
| 62.68 W (HDD Hibernation) |
| British Thermal Unit | 497.14 BTU/hr (Access) |
| 213.74 BTU/hr (HDD Hibernation) |
| Notes | Power consumption is measured when it is fully loaded with Synology 8TB HAT5300-8T hard drive(s). |
| Noise Level Testing Environment: Fully loaded with Seagate 2TB ST2000VN000 hard drive(s) in the idle state. Two G.R.A.S. Type 40AE microphones, each set up 1 meter away from the Synology NAS at the front and rear. Background noise: 16.49-17.51 dB(A), Temperature: 24.25-25.75degreesC, Humidity: 58.2-61.8% |
| Temperature |
| Operating Temperature | 0degreesC to 35degreesC (32degreesF to 95degreesF) |
| Storage Temperature | -20degreesC to 60degreesC (-5degreesF to 140degreesF) |
| Relative Humidity | 5% to 95% RH |
| Certification |
| Certification | FCC |
| CE |
| BSMI |
| VCCI |
| RCM |
| EAC |
| CCC |
| KC |
| UL |
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