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Overview

The WD Red WD40EFAX 4TB NAS Hard Drive is designed for 24/7 NAS environments with up to 8 bays. Featuring a 5400RPM spindle speed, SATA 6Gb/s interface, and optimized NASware technology, it delivers reliable, energy-efficient storage for home and small business NAS systems

WD Red NAS 4TB 3.5” 5400RPM SATA Internal Hard Drive – WD40EFAX

Model: WD40EFAX
Web Code: 19883000
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Warranty

Check with the manufacturer for details.

For Quebec residents: See the Availability Guarantee disclosure in the Specifications section below.

The Western Digital WD Red NAS 4TB Internal Hard Drive (WD40EFAX) is engineered specifically for NAS (Network Attached Storage) systems used in homes and small businesses. Built for continuous 24/7 operation, this 3.5-inch SATA hard drive offers dependable performance, low power consumption, and enhanced reliability for multi-drive environments.

With a storage capacity of 4TB, the WD40EFAX provides ample space for backups, media libraries, surveillance storage, cloud storage setups, and file sharing. Its 5400RPM rotational speed combined with a SATA 6Gb/s interface ensures smooth and stable data transfers while maintaining quiet and cool operation. The drive also includes a large 256MB cache for improved responsiveness and optimized NAS performance.

WD’s exclusive NASware firmware improves compatibility, reliability, and RAID integration, making this drive ideal for NAS enclosures with up to 8 drive bays. The WD Red series is designed to handle always-on workloads and supports workloads up to 180TB/year. Advanced vibration protection and balanced performance help maintain long-term durability in multi-bay NAS systems.

The WD40EFAX model is also known for using SMR (Shingled Magnetic Recording) technology, which is suitable for archival storage, backups, and media streaming, though some advanced RAID rebuild scenarios may benefit more from CMR-based alternatives.

For Quebec residents – Disclosure under the Consumer Protection Act

In compliance with Bill 29, Best Buy and third-party sellers on Best Buy Marketplace do not guarantee the availability of replacement parts, repair services, or maintenance information for any products. Coverage provided through any Best Buy Protection programs and applicable manufacturer warranties, if any, remain in place. Please contact the manufacturer directly for information about their availability guarantee.

Shipping Charges

Free standard shipping on all orders.

Processing Time

Most items ship within 2 business days after an order is placed*. Allow additional time for shipping to your address.
*Please note: If an item you ordered becomes unavailable, you'll be notified and a full refund will be processed within 2 business days.

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Product Category
Computer components
Return/Exchange Period
30 days
Condition
Unopened

We can only acceept returns that are in their original packaging and do recommend customers check manufacturer's warranties for exclusions.

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