Computer | Storage

Long-term FieldTest: 02.07.2021 to date


With USB Enclosure also useable externally on a MacBook

I had been interested in such SSDs for a long time, but since I have only used notebooks for years and did not bother with external enclosures, I had not used internal storage media as external ones before.
But now I have bought two in quick succession …


While browsing the Amazon shop at night, I not only look for and find an external USB hard drive for backups, but also become aware of external hard drive enclosures that are also suitable for SSDs. Because SSDs for installation in PCs are generally cheaper than external SSDs with USB interfaces, I immediately look for a large SSD with the latest technology at an acceptable price and find what I'm looking for: WD Blue SATA SSD 4 TB.


It wasn't until I went to Amazon to look for external hard drive enclosures for my test reports that I discovered the newer version with aluminium. This model matches the Apple design even better and its electronics can even handle max. 10 Gbps instead of max. 6 Gbps like the ABS plastic variant.
In the meantime, I have decided to buy an SSD instead of another hard drive because I am very satisfied with the first one. So the price reduction to 386.85 EUR is just what I need!



Order at Amazon: WD Blue SATA SSD 4 TB (411.82 EUR)
and in addition:
UGREEN 2.5 inch SATA enclosure made of ABS plastic (16.99 EUR).
Amazon confirms the order and states the delivery date 03.07.2021.
30.06.2021: Amazon's shipping confirmation; delivery date 02.07.2021.
02.07.2021: DHL has put Amazon's announcement into practice.


Order at Amazon: WD Blue SATA SSD 4 TB (386.85 EUR)
and in addition:
UGREEN 2.5 inch SATA enclosure made of ABS and aluminium (22.09 EUR).
13.07.2021: Amazon's shipping confirmation; delivery date 14.07.2021.
14.07.2021: DHL has put Amazon's announcement into action.


Western Digital Blue SATA SSD 4 TB

Tech Specs

Product specifications according to manufacturer



WD Blue SSD in 2.5-inch housing (height: 7 mm)
Model number: WDS400T2B0A
Also available with: 2 TB, 1 TB, 500 GB, 250 GB




Sequential reads at up to 560 MB/s
Sequential writes at up to 530 MB/s
Random reads up to 95,000 IOPS
Random writes up to 82,000 IOPS
Durability: 600 TBW

Power Adapter

Active power consumption on average: 60 mW
Max. Reading mode: 3,000 mW
Max. Write mode: 3,800 mW
Snooze: 56 mW
DevSlp: 5–12 mW


MTTF: up to 1.75 million hours

Operating Conditions

Operating temperature: 0 °C to 70 °C
Temperature when not in use: -55 °C to 85 °C
Vibration (in operation): 5.0 G rms, 10–2,000 Hz
Vibration (when not in use): 4.9 G rms, 7–800 Hz
Shocks: 1,500 G at 0.5 ms half sine wave
Certifications: FCC, UL, TÜV, KC, BSMI, VCCI, Morocco
Manufacturer's warranty: 5 years

Dimensions & Weight

100,2 mm x 69,85 mm x 7,00 mm
57,9 g


External Housing

Since I want to run these two SSDs on an Apple MacBook Air (2020), I bought external USB enclosures for them. Initial operation is quite simple: carefully slide them into the external enclosure, close the lid and connect them to the docking station or MacBook via Thunderbolt or USB-C cable. If you have room for another 2.5-inch hard drive in your computer, you can install the SSD directly. If this SSD is intended as a backup medium, the solution with external enclosure is also recommended if you still have a free space in your computer (PC/Mac/notebook). This is because an SSD/hard disk that is connected at any time is not safe from encryption Trojans (so-called “ransomware”).

I use one of the two SSDs as a permanent storage medium and the second is connected as a backup medium only when needed.

Windows User

… Windows users simply connect the hard disk and give it a nicer name to distinguish it and because otherwise a cryptic long name might be displayed. I always give my hard disks their correct designation as a name including hard disk capacity (as suffix) like this: “WD Elements Portable 5TB”. This is clearer because over time you will accumulate some storage devices or at least connect them temporarily and confusion can end dramatically.

Mac User

… if you do not need to use the hard disk for data exchange across operating system boundaries, i.e. it is only used in the “Apple universe”, connect the hard disk and select in the Finder:
Go to/Hard Disk Utility. New hard disks/SSDs not yet formatted for macOS have always been displayed in the left column at the top with their technical “cryptic” names.
So click on the name for your new drive that Disk Utility displays the data of this storage and look very carefully to see whether it is really the right storage that is about to be reformatted, because all on this storage will be erased irretrievably!

In the macOS version 11.4 (Big Sur) used at the time of the test, “Delete” must now be selected from the menu at the top, after which I can give my new hard disk a pretty name and select file format (see tips below).

Use as ordinary Storage

APFS Volume • APFS (upper/lower case, encrypted)
This allows you to use the very convenient hard disk encryption.

Do you use a good password safe like Strongbox or just the Apple keychain? Then generate a secure long password and store it there. I manage my passwords using Strongbox and also store those for hard drives in Apple's keychain, which decrypts hard drives fully automatically after initial setup as soon as access is required from the unlocked MacBook. Those who don't trust Apple use a password manager, it's just one step more.

Use as “Time Machine”

Mac OS Extended (upper/lower case, journaled, encrypted)
The file format strongly recommended by Apple for “Time Machine”
(system tool for automatic backup in the background).

Tip: use several Backup Media

Do not rely solely on the backups of an “SSD as a time machine”. Better store indispensable data on several other media, e.g. encrypted on an external SSD and a USB stick or SD card, both of which you can store at home or in a safe deposit box (safe from fire or water damage).

Protection against Ransomware Trojans

In addition, back up all irretrievable data regularly on another external hard drive (or SSD), which, if possible, should not remain permanently plugged into the computer.

Ransomware (extortion Trojans) have long been available for macOS as well, so a backup hard drive/SSD that is not permanently connected is important!


Photo: WD Blue SATA SSD 4 TB top side

Photo: WD Blue SATA SSD 4 TB top side

Photo: WD Blue SATA SSD 4 TB, back with label (Made in Malaysia)

Photo: WD Blue SATA SSD 4 TB, back with label (Made in Malaysia)

Photo: WD Blue SATA SSD 4 TB, back wit label (Made in China)

Photo: WD Blue SATA SSD 4 TB, back wit label (Made in China)


  • no moving parts, therefore insensitive to vibrations
  • low energy requirement
  • high reading speed
  • high writing speed
  • high reliability
  • fair price/performance ratio
  • 5 years warranty


  • none


Highly recommended!
I am very satisfied with this solution. The speed is super!
By the way: this website (200 MB) is backed up within 10 seconds!

As soon as I have a need again, I will buy this model again.


Also available with: 2 TB, 1 TB, 500 GB, 250 GB.

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