LaCie d2 Thunderbolt 3, analysis of an external hard drive

An external hard drive has many utilities even today that the cloud has hoarded everything. We can back up to iCloud, Google Drive or OneDrive for example. We can also save here files that we do not use every day and download them only when we need to. But none of these solutions will be as fast as an external hard drive connected to your Mac. Nowadays if you want a storage extension of your Mac surely the best option is an external physical storage unit, by speed and reliability.

But of course, which one to choose? Finding the right external hard drive is not easy. Not because of the absence of options but precisely because there are so many different options, we must choose the one that best suits us now and in the medium term. If there is one field where there may not be many doubts it is in the professional, where the LaCie brand has made an important hole in the desktop storage with its d2 range. We’ve tested the LaCie d2 Thunderbolt 3 and, as well as being a performance beast, it’s great for accompanying your work Mac.

LaCie d2 Thunderbolt 3

LaCie’s storage units have the peculiarity of having an excellent design (usually Neil Poulton’s creations) that fit very well with the touch of Jony I’ve aluminum on macs. But this is the least, what really makes them good is the reliability and speed they reach, being up to the most powerful Macs that Apple sells.

Features and Specifications



13 x 6 x 21.7 cm


2.2 kg


6TB, 8TB or 10TB


HDD Disc


Up to 240 MB/s


Thunderbolt 3 over USB-C and USB-A


From $37, $32 USD

LaCie’s quirky design discussed above is instantly noticeable to take the hard drive out of the box. It is heavy but stable and with all the pieces well cohesive. For example, the hard drive case is a single folded aluminum sheet, similar to what Apple does with MacBooks, they are small details but they make a difference and when using the product gives you the feeling of being really of quality. Regardless of whether it is or not.

In addition to the hard drive itself inside the box we find the power cables, endless adapters for different plugs, the Thunderbolt 3 cable by USB-C, a USB-C to USB-A adapter and the quick installation guide. Here you have to take into account an important topic, if your Mac does not support Thunderbolt 3 you will have to connect it by the adapter to USB-A, so the speeds may vary. Another option is to get a Thunderbolt 3 (USB-C) to Thunderbolt 2 adapter, Apple has a support page with details if you find yourself in this situation.

LaCie’s d2 Thunderbolt 3 has a minimum capacity of 6 TB, but has another 8 TB model and more than 10 TB. It therefore depends on the needs of each user when choosing storage. Thunderbolt 3, USB and USB-C connections, as well as the power port. As for the weight, it reaches 2.2 kg, you will notice it very heavy, because its size is only 13 x 6 x 21.7 cm.

Finally, what makes these storage drives stand out is their overall transfer speed and performance. Depending on the manufacturer, it can achieve maximum speeds of 240 MB/s using Thunderbolt 3. However, these speeds are always in optimal conditions and with adequate equipment and at the height.

LaCie d2 Thunderbolt 3

There are other features of the LaCie d2 Thunderbolt 3 that we haven’t been able to test but are present. Thanks to the USB-C connection, a single port can be used for various functions, for example while the LaCie d2 Thunderbolt 3 is connected to a MacBook via USB-C the latter can be charged by powering the external disk. Thunderbolt 3 power can also be used to chain multiple Thunderbolt 3 d2 disks, two 4K displays, or a 5K display via a single port. When Apple said that the MacBook had a single USB-C port to dominate them all it referred to these kinds of advantages.

Day-to-day with a LaCie d2 Thunderbolt 3

In recent days I have been using a LaCie d2 Thunderbolt 3 as an external storage unit on my computer and daily work. LaCie d2 Thunderbolt 3 shared a desktop with a 27-inch iMac in mid-2017 with macOS High Sierra and between the two they have managed dozens of GBs in multimedia files. No effort.

Installing the LaCie d2 Thunderbolt 3

The first thing has been the installation, for this laCie offers us its own installation wizard that allows us to format the disk and be able to start using it. This is normal on any storage device, but it’s a process you can also do with external tools like Apple’s own, Disk Utility. LaCie’s wizard however when running it allows us to format the disk and create different partitions, being able to register the product in the LaCie database.

My recommendation in this regard is to register the product using the LaCie wizard, so in case of any problem we can manage it with the manufacturer more easily. But if you want to customize the disc your way and without complicating yourself, format it with Disk Utility. In either case, it is a mandatory step to be able to start using the disk.

Actual LaCie d2 Thunderbolt 3 read and write speeds

The important thing about these types of devices is that they perform well to what they promise and to the needs of each user. The LaCie d2 Thunderbolt 3 isn’t going to be as fast as your Mac with APFS file system and SSD storage, but it will be faster than most hard drives. In this case a series of tests have been performed to see how it behaves in small file transfer and large file transfer. Or what’s the same, when a user has to copy hundreds of photos and when a user has to copy multiple videos or movies. The tests have therefore been:

Copy from the computer to the disk and vice versa a total of 10 GB in photographs (approximately 700 photographs of about 14 MB of average each).

Copy from computer to disk and vice versa a total of 10 GB in videos (two large files of approximately 5 GB each).

Each of the tests has been performed a total of three times and the average has been taken out of them. While it has not reached the 240 MB/s speed promised by the manufacturer… has come quite close, more in reading than in writing.

Copying small files the LaCie d2 Thunderbolt 3 has an average speed of 174.3 MB/s write and 229.5 MB/s read.

Copying large files the LaCie d2 Thunderbolt 3 has an average speed of 183.6 MB/s write and 231.4 MB/s read.

LaCie d2 Thunderbolt 3, is it worth it as an external disk?

We have to start from the premise that the LaCie d2 Thunderbolt 3 is a disk of the professional range of LaCie, this means that it is focused on a certain sector with specific needs and possibilities, usually greater than those of a home user. The LaCie d2 Thunderbolt 3 is up to what it promises, above the average you expect on an external disk and on the line with other manufacturers in speed and performance. As an extra point, its incredibly solid and stable design. It’s a record that you can’t figure out if it’s true or not, but you get the feeling that’s going to last you for a lifetime.

The price of the LaCie d2 Thunderbolt 3 starts at 370.32 US for the 6 TB model, 497.67 euros for the 8 TB model and 570.56 euros for the 10 TB maximum capacity model. Is it expensive? The truth is that there are not many alternatives with this type of connections and with so much capacity, but because of its features the LaCie d2 Thunderbolt 3 has a more than consistent price in a work area, where you need reliability and speed.