BUFFALO WS5420DN16W5 – TeraStation WS5020 16TB 4-Bay Windows Server NAS
Overview
The BUFFALO WS5420DN16W5 is a TeraStation WS5020 Series 4-bay desktop NAS configured with four 4TB NAS-dedicated HDDs for 16TB of installed storage. It runs Windows Server IoT 2025 for Storage Workgroup and provides a Windows-based file server platform for business storage, backup, replication, and shared file access.
The exact WS5420DN16W5 configuration uses software RAID and ships with RAID 5 as the default configuration. Buffalo specifies 12TB of RAID 5 capacity from the 16TB installed drive capacity, with RAID 1 and RAID 0 also supported.
Technical Information
The WS5420DN16W5 uses an Intel Atom C3338 processor operating at 1.50GHz, with Turbo Boost up to 2.20GHz, and 8GB of DDR4 ECC memory. The four installed NAS-dedicated HDDs use the internal Serial ATA III interface.
Windows Server IoT 2025 for Storage Workgroup provides Windows Server-based file-server capabilities, including Windows Server Backup, Active Directory integration, SMB file services, scheduled backup, DFS replication, BitLocker drive encryption, and cloud storage integration. The system also supports remote monitoring and configuration through Buffalo KikiNavi.
Compatibility
The WS5420DN16W5 has four 3.5-inch drive bays, all populated with 4TB NAS-dedicated HDDs. Supported RAID modes are RAID 5, RAID 1, and RAID 0. Hot-swapping is supported, while Buffalo specifies that hot-spare functionality is not supported on this exact model.
Network connectivity includes one 10GBASE-T RJ-45 port and two 1000BASE-T RJ-45 ports. The 10GbE interface supports 10Gbps, 5Gbps, 2.5Gbps, 1Gbps, and 100Mbps operation. The two 1GbE ports support 1000Mbps, 100Mbps, and 10Mbps operation. The documented network file protocol is SMB, while TCP/IP and UDP are supported network protocols.
The system provides two USB 3.2 Gen 1 Type-A ports with transfer rates up to 5Gbps. An LCD display provides system information including link speed, drive usage, hostname/IP address, time, installed operating system, and status information.
Key Features
- 16TB installed capacity using four 4TB NAS-dedicated HDDs.
- Four-bay desktop chassis with all four drive bays populated.
- One 10GbE RJ-45 port plus two 1GbE RJ-45 ports.
- Intel Atom C3338 processor with 8GB DDR4 ECC memory.
- Windows Server IoT 2025 for Storage Workgroup with factory RAID 5 and 12TB RAID 5 capacity.
Applications
- Windows-based business file server deployments
- Centralized SMB file storage
- Business backup and scheduled backup operations
- Active Directory-integrated storage
- DFS replication between Windows-based storage systems
DC Supplies Product Note
The WS5420DN16W5 is the 16TB four-drive configuration of the WS5420DN Windows Server NAS platform. Buffalo specifies four 4TB drives, factory RAID 5, and 12TB RAID 5 capacity for this exact MPN. All four drive bays are populated, so increasing internal raw capacity requires replacing installed drives.
Specifications
| Specification | Details |
|---|
| Brand | BUFFALO |
| Part Number / MPN | WS5420DN16W5 |
| Product Type | Windows Server NAS |
| Series | TeraStation WS5020 |
| Form Factor | Desktop |
| Drive Bays | 4 |
| Included Drives | 4 |
| Drive Configuration | 4 x 4TB |
| Total Installed Capacity | 16TB |
| Drive Type | NAS-dedicated HDD |
| Drive Size | 3.5-inch |
| Drive Interface | Serial ATA III, up to 6Gbps |
| RAID Type | Software RAID |
| Factory RAID | RAID 5 |
| RAID 5 Capacity | 12TB |
| Supported RAID | RAID 5/1/0 |
| Processor | Intel Atom C3338 |
| Processor Speed | 1.50GHz; Turbo Boost up to 2.20GHz |
| CPU Cores / Threads | 2 cores / 2 threads |
| Memory | 8GB DDR4 ECC |
| 10GbE Network Port | 1 x 10GBASE-T RJ-45 |
| Gigabit Ethernet Ports | 2 x 1000BASE-T RJ-45 |
| Supported Ethernet Speeds | 10Gbps/5Gbps/2.5Gbps/1Gbps/100Mbps/10Mbps |
| Network Protocols | TCP/IP, UDP |
| Network File Protocol | SMB |
| USB Ports | 2 x USB 3.2 Gen 1 Type-A |
| USB Transfer Rate | Up to 5Gbps |
| LCD Display | Yes |
| Windows Server Backup | Yes |
| Replication | Yes |
| Failover | No |
| Active Directory Integration | Yes |
| Subfolder Access Restrictions | Yes |
| Cloud Storage Integration | Yes |
| KikiNavi Remote Management | Yes |
| KikiNavi Remote Configuration | Yes |
| Hot Swap | Yes |
| Hot Spare | No |
| Port Trunking / NIC Teaming | Yes |
| Drive Encryption | Yes, BitLocker on supported basic disks |
| iSCSI Target | Yes |
| NAS / iSCSI Target Simultaneous Use | No |
| SSD Caching | No |
| Wake on LAN | Yes |
| Operating System | Windows Server IoT 2025 for Storage Workgroup |
| Maximum Power Consumption | 85W |
| Power Supply | Internal AC 100–240V, 50/60Hz |
| Operating Temperature | 0–40°C |
| Operating Humidity | 10–85% non-condensing |
| Cooling | 1 x 92mm ball-bearing fan |
| Dimensions (W x H x D) | 170 x 215 x 230mm |
| Weight | Approximately 7.4kg |
| Warranty | 3 years, including HDDs |
| Country of Origin | Japan |
| TAA Compliant | Yes |
FAQs
How much storage is included with the BUFFALO WS5420DN16W5?
The WS5420DN16W5 includes four 4TB NAS-dedicated HDDs for 16TB of installed raw capacity.
What is the factory RAID configuration?
The exact WS5420DN16W5 ships with software RAID 5 configured as the default, providing 12TB of RAID 5 capacity before the operating-system space used on the drives.
Which RAID levels are supported?
The system supports RAID 5, RAID 1, and RAID 0.
What operating system does the WS5420DN16W5 use?
The NAS runs Windows Server IoT 2025 for Storage Workgroup, providing Windows-based file-server and storage-management capabilities.
What network ports are provided?
The WS5420DN16W5 provides one 10GbE RJ-45 port and two 1GbE RJ-45 ports.
Does the system support hot swapping?
Yes. Buffalo specifies hot-swap support for the storage drives. Hot-spare functionality is not supported on this exact model.
