BUFFALO WS5420RN48W5 – TeraStation WS5020 48TB 4-Bay 1U Windows Server NAS
Overview
The BUFFALO WS5420RN48W5 is a 4-bay, 1U rackmount NAS in the TeraStation WS5020 series, configured with four 12TB NAS-grade hard drives for 48TB of total installed capacity. It runs Windows Server IoT 2025 for Storage Workgroup Edition and is designed for Windows-based file serving, centralized storage, backup, replication, and business network environments.
Technical Information
The WS5420RN48W5 uses an Intel Atom C3338 dual-core processor operating at 1.50GHz and provides 8GB of DDR4 ECC memory. Its four 3.5-inch SATA 6Gbps drive bays are populated with four 12TB HDDs. Storage uses software RAID, with RAID 5 configured by default and RAID 0, RAID 1, RAID 5, and JBOD supported.
Network connectivity includes one 10GBASE-T RJ-45 port and two 1000BASE-T RJ-45 ports. The system supports 10GbE, 5GbE, 2.5GbE, Gigabit Ethernet, 100Mbps, and 10Mbps operation through its network interfaces.
Windows Server IoT 2025 for Storage Workgroup Edition provides Windows-based file-server functionality with support for SMB, Active Directory integration, data deduplication, iSCSI, replication, Windows Server Backup, cloud storage integration, and remote management. Buffalo also supports SMB over QUIC and enhanced Windows Server security capabilities on the WS5020 IoT 2025 platform.
Compatibility
The WS5420RN48W5 is intended for Windows-based business storage environments and integrates with Microsoft services including Azure and OneDrive. Its 10GBASE-T RJ-45 interface can connect directly to compatible copper 10GbE switches, while the two 1000BASE-T ports provide standard Gigabit Ethernet connectivity.
The four internal bays use 3.5-inch SATA drives. The exact model includes four 12TB drives and supports RAID 0, RAID 1, RAID 5, and JBOD/individual-disk configurations. Buffalo identifies OP-HD12.0N as the compatible 12TB replacement drive.
Key Features
- 48TB installed capacity using four 12TB NAS-grade HDDs
- 4-bay 1U rackmount chassis with software RAID and hot swapping
- Windows Server IoT 2025 for Storage Workgroup Edition
- 1 × 10GBASE-T and 2 × 1000BASE-T RJ-45 network interfaces
- 8GB DDR4 ECC memory with RAID 5 factory configuration
Applications
- Windows-based business file-server deployments
- Centralized network storage and backup
- Rackmount storage for server rooms and data centers
- 10GbE storage networks using copper Ethernet infrastructure
- iSCSI, replication, cloud backup, and Windows Server Backup environments
DC Supplies Product Note
The WS5420RN48W5 is the 48TB configuration of the 4-bay WS5420RN platform, with four 12TB drives installed and RAID 5 configured by default. The exact configuration combines Windows Server IoT 2025, 10GbE connectivity, 8GB ECC memory, and hot-swappable storage in a compact 1U rackmount chassis.
Specifications
| Specification | Details |
|---|
| Brand | BUFFALO |
| Part Number / MPN | WS5420RN48W5 |
| Product Type | Rackmount Windows Server NAS |
| Series | TeraStation WS5020 / WS5420RN |
| Form Factor | 1U Rackmount |
| Operating System | Windows Server IoT 2025 for Storage Workgroup Edition |
| Total Installed Capacity | 48TB |
| Included Drives | 4 × 12TB NAS-grade HDD |
| Drive Bays | 4 × 3.5-inch |
| Drive Interface | SATA 6Gbps |
| RAID Type | Software RAID |
| Default RAID | RAID 5 |
| Supported RAID | RAID 0, RAID 1, RAID 5, JBOD / Individual Disks |
| RAID 5 Capacity | 36TB |
| RAID 1 Capacity | 24TB |
| RAID 0 Capacity | 48TB |
| Hot Swap | Supported |
| Hot Spares | Supported |
| CPU | Intel Atom C3338, 1.50GHz, Dual-Core |
| Memory | 8GB DDR4 ECC |
| 10GbE | 1 × 10GBASE-T RJ-45 |
| Gigabit Ethernet | 2 × 1000BASE-T RJ-45 |
| USB | 3 × USB 3.0 Type-A |
| Network Protocols | TCP/IP, CIFS/SMB, AFP, FTP, SFTP, NFS, SNMP |
| iSCSI | Supported |
| Replication | Supported |
| Windows Server Backup | Supported |
| Active Directory | Supported |
| Cloud Service Integration | Supported |
| Remote Management | Buffalo KikiNavi |
| Power Input | AC 100–240V, 50/60Hz |
| Maximum Power Consumption | 100W |
| Data Transfer Power Consumption | 61.7W |
| Idle Power Consumption | 58.7W |
| Standby Power Consumption | 4.9W |
| Operating Temperature | 0–40°C |
| Operating Humidity | 10–85% non-condensing |
| Dimensions | 16.9 × 16.9 × 1.7 in |
| Weight | Approximately 19.6 lb / 8.9kg |
| Compatible Replacement Drive | OP-HD12.0N |
| Warranty | 3 years |
| Country of Origin | Japan |
| TAA Compliant | Yes |
FAQs
What is the storage capacity of the BUFFALO WS5420RN48W5?
The WS5420RN48W5 has 48TB of total installed storage using four 12TB hard drives.
What RAID mode is configured by default?
Buffalo specifies RAID 5 as the default configuration. With four 12TB drives, the listed RAID 5 capacity is 36TB before operating-system overhead.
Does the WS5420RN48W5 support 10GbE?
Yes. The system provides one 10GBASE-T RJ-45 port and two 1000BASE-T RJ-45 ports. The 10GbE interface also supports 5GbE and 2.5GbE operation.
What operating system does the WS5420RN48W5 use?
The system runs Windows Server IoT 2025 for Storage Workgroup Edition, providing a Windows Server-based platform for business storage and file-server deployments.
Which replacement drive is specified for the WS5420RN48W5?
Buffalo identifies the OP-HD12.0N as the compatible 12TB replacement drive for the WS5420RN48W5.
