Western Digital Red 4TB SATA Internal Desktop NAS Hard Drive (WD40EFRX)

Our formula of success has led growth of WD Red into higher capacities and expansion into new 2.5-inch solutions. We now offer a broader, more comprehensive portfolio of NAS hard drives for our customers. It is not just about NAS drives, it is REDvolutionary.

Next generation experience
Every component, line of code, and product decision was built on our passion and determination to deliver the best NAS experience.The next generation of WD Red hard drives delivers on this promise with massive capacity and NASware 2.0, which further improves drive reliability and protects your data in the event of a power loss or power disruption.

Experienced in NAS
In all of our cultures around the world, first impressions are what leave a mark. With superior technology that is driven to impress, WD Red is a reflection of the most extensive NAS partner compatibility-testing list that is available on the market*. That means when you buy a NAS enclosure, you can trust that WD Red will be the most compatible drive available. Our pride is in our product and our vision is shared with our customers.

NAS for home
Take your connected home environment to the next level with a NAS system that is equipped with WD Red hard drives and enjoy streaming your media, backing up your computers, file sharing and managing your digital content faster and easier.WD Red's NASware 2.0 experience with increased compatibility makes sharing from your mobile device, computer, TV, stereo and more an instant gratification. And with capacities now available in 4 TB, a 5-bay NAS system can hold close to 20 terabytes of data!

NAS for small business
Increase the efficiency and productivity of your small business with WD Red hard drives for your 1 to 5 bay NAS system. WD Red comes equipped with NASware 2.0, which increases system compatibility allowing for seamless integration with your existing network infrastructure. Add value to your business by enabling your employees to quickly share their files and back up folders reliably with WD Red NAS hard drives in your NAS solution.

Exclusive NASware 2.0 technology
Our exclusive technology, NASware 2.0, makes WD Red thrive in the demanding small-NAS environment. By adding WD Red to your NAS system, not only is everything more efficient and reliable, you get to enjoy a REDvolutionary NAS experience.

3D Active Balance Plus
Our enhanced dual-plane balance control technology significantly improves the overall drive performance and reliability. Hard drives that are not properly balanced may cause excessive vibration and noise in a multi-drive system, reduce the hard drive life span, and degrade the performance over time.

Enhanced reliability
Since your NAS system is always on, a highly reliable drive is essential. With a 35% MTBF improvement over standard desktop drives, the WD Red drive with NASware 2.0 is designed and manufactured to be a more reliable and robust solution.

The right choice
The right choice for NAS, no other drive is designed specifically for home and small office NAS systems and PCs with RAID.

NAS compatibility
Advanced firmware technology built into every WD Red drive, NASware 2.0 enables seamless integration, robust data protection and optimal performance for systems operating in NAS and RAID environments.

The secret is the next-generation technology
WD's next generation NASware 2.0 technology improves NAS storage performance by reducing common hard drive concerns in NAS systems. This includes concerns for things like compatibility, integration, upgrade ability, reliability and cost of ownership that are experienced with a hard drive designed for desktop computers.

Energy efficient and money saving
We keep power consumption low, which keeps your NAS system happy, and your wallet too.

Longer warranty coverage
WD Red hard drives are backed by a 3-year limited warranty for greater peace of mind.

Lower operating temperatures
Reduce your electricity bill and carbon footprint with WD Red drives. Innovative technology reduces power consumption and lowers the operating temperature, resulting in a more reliable and affordable solution for always on 24x7 NAS environments.

Technical Details

Model

Brand : Western Digital
Model : WD40EFRX

Specifications

Interface : SATA 6 Gb/s

Performance Specifications 
Rotational Speed : IntelliPower
Buffer Size : 64 MB

Transfer Rates
Buffer To Host (Serial ATA) : 6 Gb/s (Max)

Physical Specifications 
Formatted Capacity : 4,000,787 MB
Capacity : 4 TB
Form Factor : 3.5 Inch
User Sectors Per Drive : 7,814,037,168

Performance Specifications 

Target Performance
MTBF : 1,000,000 hours

Physical Dimensions 

English
Height : 1.028 Inches
Depth : 5.787 Inches
Width : 4.00 Inches
Weight : 1.50 Pounds

Metric
Height : 26.1 mm
Depth : 147 mm
Width : 101.6 mm
Weight : 0.68 kg

Environmental Specifications 

Shock
Operating Shock (Read) : 65G, 2 ms
Non-operating Shock : 250G, 2 ms

Acoustics
Idle Mode : 25 dBA (average)
Seek Mode 0 : 28 dBA (average)

Temperature (English)
Operating : 32° F to 158° F
Non-operating : -40° F to 158° F

Temperature (Metric)
Operating : -0° C to 70° C
Non-operating : -40° C to 70° C

Humidity
Operating : 5-95% RH non-condensing

Vibration
Operating : 0.004 g²/Hz (10 to 300 Hz)
Non-operating : 0.05 g²/Hz (10 to 300 Hz)

Operating
Linear : 20-300 Hz, 0.75G (0 to peak)

Electrical Specifications 

Current Requirements

12 VDC
Read/Write : 250 mA
Idle : 230 mA
Standby : 7 mA
Sleep : 7 mA

5 VDC
Read/Write : 280 mA
Idle : 260 mA
Standby : 105 mA
Sleep : 105 mA

Power Dissipation
Read/Write : 4.50 Watts
Idle : 3.30 Watts
Standby : 0.40 Watts
Sleep : 0.40 Watts

Compatibility
 
Operating System
Compatibility : Windows/Mac/Linux