WD My Cloud Expert Series 24TB EX4100 4-Bay NAS Server

The WD My Cloud EX4100 Expert Series 24TB is WD’s flagship prosumer 4-bay NAS, purpose-built for users who demand serious storage performance, flexible RAID protection, and professional-grade private cloud access. Pre-populated with ultra-reliable WD Red NAS drives purposely built to thrive in 24×7 NAS environments, and powered by a Marvell ARMADA 388 1.6 GHz dual-core processor and 2 GB DDR3 memory delivering ultra-fast transfer speeds of 114 MB/s upload and 108 MB/s download, the EX4100 is ready to handle high-performance media streaming, simultaneous multi-user access, and enterprise-class backup workflows right out of the box.

Superior Performance for Demanding Workloads

Powered by a Marvell ARMADA 388 1.6 GHz dual-core processor with 2 GB DDR3 RAM, the EX4100 handles simultaneous tasks — 4K media transcoding via Plex, multi-user file sharing, background backup jobs, and cloud sync — without performance degradation. Dual Gigabit Ethernet ports enable link aggregation for enhanced network performance, delivering the best possible HD media streaming experience, while also providing network redundancy should one connection fail.

Advanced RAID for Every Use Case

RAID 0 delivers enhanced system performance, RAID 1 provides mirrored data protection, RAID 5 offers data protection with best capacity, and RAID 10 delivers fast performance with ultimate data reliability. Combined with AES 256-bit volume encryption, data stays protected at rest and across the network. Tool-less and tray-less drive bays make hot-swap drive replacement effortless.

Private Cloud Without Subscriptions

Through My Cloud OS 5, the My Cloud mobile app, and MyCloud.com, users access, upload, share, and stream files from any device — smartphone, tablet, or computer — without recurring subscription fees. Easily transfer content between the NAS and supported cloud services like Dropbox or Google Drive.

Media Streaming & One-Touch USB Copy

The built-in Twonky DLNA-certified media server seamlessly streams HD videos, photos, and music to media players, Smart TVs, gaming consoles, and other DLNA-certified devices. Plex Media Server is downloadable via the dashboard for rich, organised library streaming. The one-touch copy button on the front panel automatically copies all photos, videos, and music from a connected USB device or camera directly to the EX4100.

Comprehensive Backup

WD SmartWare Pro enables customised PC backup scheduling, while Mac users have full access to Apple Time Machine. Remote NAS-to-NAS backup and cloud backup to Amazon S3, Dropbox, and supported cloud services add additional data protection layers.

Backed by a 2-year limited hardware warranty (3-year for included WD Red drives), the EX4100 is the definitive private cloud NAS for professionals and growing small offices.

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Technical Specifications

Hardware

• Processor: Marvell ARMADA 388, 1.6 GHz Dual-Core (ARM)
• RAM: 2 GB DDR3 (fixed — not user-upgradeable)
• Drive Bays: 4x 3.5″ SATA III (internal, hot-swappable)
• Pre-Installed Drives: 4x WD Red 6TB (5400 RPM, SATA III, NASware)
• Total Raw Capacity: 24TB
• Drive Installation: Tool-less, tray-less hot-swap

Transfer Performance

• Upload Speed: Up to 114 MB/s
• Download Speed: Up to 108 MB/s

RAID & Storage

• RAID Modes:
• RAID 0 — striping, 24TB usable (max performance)
• RAID 1 — 2-drive mirror, 12TB usable (redundancy)
• RAID 5 — parity, 18TB usable (protection + capacity)
• RAID 10 — stripe + mirror, 12TB usable (performance + redundancy)
• JBOD / Spanning — non-RAID flexible
• File Systems: EXT4 (internal), FAT32/NTFS/HFS+ (USB)
• Encryption: AES 256-bit volume-level encryption

Connectivity

• Network: 2x Gigabit Ethernet RJ45 (10/100/1000 Mbps)
• Link aggregation (802.3ad LACP)
• Failover / redundancy
• USB Ports: 3x USB 3.0 Type-A
• 1x front panel (with one-touch copy button)
• 2x rear panel (expansion storage / printer)
• One-Touch Copy: Front-panel button for instant USB-to-NAS file copy

Network Protocols & Services

• File Sharing: SMB/CIFS (Windows), AFP (Mac), NFS
• FTP: FTP and SFTP server
• Media Server: Twonky DLNA-certified (built-in), Plex Media Server (downloadable)
• Discovery: Bonjour, DLNA/UPnP
• DDNS: Built-in dynamic DNS
• iSCSI: Not supported on EX4100
• NTP: Network Time Protocol client

Software & OS

• Operating System: My Cloud OS 5
• Admin Interface: Web-based dashboard (HTTP/HTTPS)
• Mobile App: My Cloud (iOS & Android)
• Web Portal: MyCloud.com (browser-based remote access)
• Sync: WD Sync (automatic Windows & Mac folder sync)
• API: REST API support

Backup Solutions

• Windows: WD SmartWare Pro, Acronis True Image for WD
• Mac: Apple Time Machine, Acronis True Image for WD
• NAS-to-NAS: Remote NAS backup (rsync)
• Cloud Backup: Amazon S3, Dropbox, Google Drive, Acronis Cloud, ElephantDrive

Media & Apps

• Built-in: Twonky DLNA media server
• Downloadable via Dashboard:
• Plex Media Server
• Dropbox
• WordPress
• Amazon S3
• ElephantDrive

Security

• Volume Encryption: AES 256-bit
• User Management: User and group accounts with per-share permissions
• Access Control: Public/private share links, per-user storage quota
• Remote Access: Secure HTTPS via MyCloud.com

Physical Specifications

• Form Factor: Desktop (vertical orientation)
• Dimensions (H x W x D):
• 9.13 x 6.69 x 7.56 in
• 232 x 170 x 192 mm
• Weight (with drives): 6.32 kg / 13.94 lbs
• Housing: Metal and plastic composite
• Colour: Black
• Cooling: Internal active fan
• Drive Mounting: Vertical, tool-less tray-less bays
• LED Indicators: Power, per-bay drive activity, network activity
• Buttons: Power, one-touch USB copy (front)

Power

• Input: 100-240V AC, 50-60Hz (auto-switching)
• Output: 19V / 4.74A (external AC adapter)
• Typical Consumption: ~35W (operating with 4 drives)
• Sleep Mode: ~8W (HDD sleep)
• Power Schedule: Scheduled power on/off supported
• Wake on LAN: Supported

Environmental

• Operating Temperature: 5°C to 35°C (41°F to 95°F)
• Storage Temperature: -20°C to 65°C (-4°F to 149°F)
• Operating Humidity: 8% to 90% non-condensing
• Storage Humidity: 5% to 95% non-condensing

Compatibility

• Windows: Windows 7, 8.1, 10, 11
• Mac: macOS (see WD compatibility page for current supported versions)
• Browsers: Chrome, Firefox, Safari, Edge (latest versions)
• Mobile: iOS, Android (current My Cloud app requirements)
• Streaming: Plex-certified players, DLNA-compatible Smart TVs, PlayStation, Xbox, Chromecast

Certifications

• FCC, CE, RCM, VCCI
• RoHS compliant
• UL safety

Package Contents

• 1x WD My Cloud EX4100 NAS (4x WD Red 6TB pre-installed)
• 1x AC power adapter (19V / 4.74A)
• 1x Power cord (region-specific)
• 1x Cat5e Ethernet cable
• 1x Quick install guide

Warranty & Support

• NAS Warranty: 2-year limited hardware warranty
• WD Red Drive Warranty: 3-year limited warranty
• Support: WD online support portal, community forums, phone/chat
• Firmware: OTA automatic firmware update notifications

Capacity Variants

• 0TB — Diskless (BYO drives)
• 8TB — 4x 2TB WD Red
• 16TB — 4x 4TB WD Red
• 24TB — 4x 6TB WD Red (this model)
• 32TB — 4x 8TB WD Red
• 40TB — 4x 10TB WD Red