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How to choose the right portable SSD

The top speeds cost top dollar, but you might not need the fastest drive

The price of an external storage drive is tied to a few factors: the amount of storage capacity you’re looking for, how fast the drive is at transferring your files, and its physical size.

At this point, high-capacity external drives that require power adapters are surprisingly inexpensive. This is a great option for some, especially if lugging it around isn’t a big deal, or you rarely feel the need to unplug it. But those who are looking for something smaller, particularly a more travel-friendly USB-C drive that doesn’t compromise on storage capacity or speed, have a few different roads to take. As you might expect, it can get very expensive to find a drive that ticks all of these boxes. But thanks to the falling rates of SSD prices, you can get a fast external drive with a lot of storage capacity for less than you might expect.

I tested a few 1TB USB-C solid state drives ranging in price from around $160 to $450. This includes two portable SSDs from Samsung that arrive ready to go out of the box: a Samsung X5 Thunderbolt 3 1TB SSD and a Samsung T5 1TB SSD. Then, there’s a DIY external drive built with an Intel 660p NVMe 1TB SSD and a separate enclosure.

What you should know before buying a USB-C SSD

Unlike the buying process for most tech products, simply choosing the one that you think fits your workflow or budget isn’t the end of the road — or at least, it shouldn’t be. You also need to make sure that the macOS or Windows 10 machine that you’ll connect it to can take advantage of its speed. This means that you’ll need to determine the USB interface of the drive you’re interested in, then compare it to your computer’s USB-C port.

USB interfaces are confusing as is, and with USB 3.2 set to launch later in 2019, the classifications listed below will change. Though, you’ll likely continue to see products carry the following naming scheme for a while:

  • USB-C ports with USB 3.1 Gen 1 support up to 5Gbps bandwidth
  • USB-C ports with USB 3.1 Gen 2 support up to 10Gbps bandwidth
  • USB-C ports with Thunderbolt 3 support up to 40Gbps bandwidth

The ports themselves are backwards compatible, so a Thunderbolt 3 port will work just fine with drives that use the slower interfaces. But the same can’t be said for drives themselves. For instance, plugging a USB 3.1 Gen 2 drive with a laptop that can only handle USB 3.1 Gen 1 will work, but it’s a recipe that will churn out disappointment, not fast transfer speeds. If your computer has a Thunderbolt 3 port, it will work with non-Thunderbolt 3 devices, but conversely, the $450 X5 won’t work at all on a USB-C port that doesn’t support Thunderbolt 3.

For this comparison, I tested a 1TB Thunderbolt 3 external SSD, a 1TB USB 3.1 Gen 2 external SSD, and a 1TB NVMe SSD that I installed into a USB 3.1 Gen 2 external enclosure.

USB-C SSD specs

Comparison Samsung T5 Samsung X5 Intel 660p
Comparison Samsung T5 Samsung X5 Intel 660p
Capacity 1TB 1TB 1TB
Price $177.99 $449.99 $115
Drive type SATA NVMe PCIe NVMe PCIe
Interface USB 3.1 Gen 2 (up to 10Gbps) Thunderbolt 3 (up to 40Gbps) USB 3.1 Gen 2 (up to 10Gbps)

As if it weren’t complicated enough, you’ll also need to determine the type of storage that’s inside of your computer. This might seem trivial, since you’re shopping for an external drive, not a replacement for your internal drive. However, the transfer speed of an external drive lives and dies based on what the storage type inside of your computer is capable of. If you have a SATA drive (as many Windows laptops do), it may have a hard time keeping up with a fast external drive. As is the case with most computing components, your rig is only as fast as your slowest part.

These bottlenecks became apparent in the course of my testing. One of the test machines, a 2019 Razer Blade Stealth, has a Thunderbolt 3 port, which should allow for incredibly fast transfer speeds. Though, compared to the flash-based storage used in a 2016 MacBook Pro, another test machine that we used, the SATA-based storage in the Stealth had a significant negative impact on the maximum transfer speeds we saw from the X5 Thunderbolt 3 drive.

I tested the read and write speeds of each internal drive with Novabench, a free benchmarking tool available for both macOS and Windows 10. The Razer’s 256GB SATA drive performed at an average read speed of 481MB/s and an average write speed of 280MB/s. The MacBook Pro, with its 256GB SSD, put up an average read speed of around 2,200MB/s and an average write speed of around 1,300MB/s. The MacBook Pro’s bandwidth to send data to an external drive is much greater than the Razer laptop, and the difference lies in the storage types used in these machines. The Thunderbolt 3 drive suffered the biggest hit from the limitations imposed by the Razer’s SATA drive, though the non-Thunderbolt drives performed similarly on both systems.

USB-C SSD performance comparison

Comparison Samsung T5 Samsung X5 Intel 660p
Comparison Samsung T5 Samsung X5 Intel 660p
Drive type SATA NVMe PCIe NVMe PCIe
Interface USB 3.1 Gen 2 (up to 10Gbps) Thunderbolt 3 (up to 40Gbps) USB 3.1 Gen 2 (up to 10Gbps)
Advertised maximum transfer rate 540MB/s 2,800MB/s read, 2,300MB/s write 1,800MB/s read, 1,800MB/s write (when installed directly into motherboard)
Observed maximum transfer rate on macOS (sequential) 518MB/s read, 475 MB/s write on average 2,410MB/s read, 1,708MB/s write on average 933MB/s read, 910MB/s write on average
Observed maximum transfer rate on Windows 10 (sequential) 508MB/s read, 487MB/s write on average 2,280MB/s read, 598MB/s write on average 961MB/s read, 942MB/s write on average
Time to transfer 13GB file from MacBook Pro 29 seconds on average 9 seconds on average 17 seconds on average
Time to transfer 13GB file from drive to MacBook Pro 25 seconds on average 10 seconds on average 14 seconds on average
Time to transfer 13GB file from Razer Blade Stealth 33 seconds on average 39 seconds on average 29 seconds on average
Time to transfer 13GB file from drive to Razer Blade Stealth 49 seconds on average 45 seconds on average 45 seconds on average

Samsung X5 Thunderbolt 3 1TB SSD

Samsung’s X5 Thunderbolt 3 solid state drive currently costs $449 and proudly wears its premium status with an enclosure that’s fashioned like a sports car. Its design attributes to the cost, sure, but this drive’s main selling point is its Thunderbolt 3 data transfer speeds. This kind of drive is ideal for video producers who need to minimize the time between exporting and moving huge 4K video files to a drive, or even intend to use it as a working scratch disk. Any other passion or profession will benefit from the X5’s speeds, too, but at half the cost of many laptops, this is the best fit for those who regularly deal with large file transfers.

Samsung advertises a maximum transfer rate of 2,800MB/s read, 2,300MB/s write, and the MacBook Pro that I tested on came close to meeting those claims. Using the averages from benchmark apps Novabench and Blackmagic Design Disk Speed Test on macOS, I saw a 2,410MB/s read speed and 1,708MB/s write speed. It took only an average of nine seconds to transfer a 13GB file from the MacBook Pro to the X5.

On the Razer Blade Stealth, I aggregated the benchmark results from Novabench and ATTO. It managed 2,280MB/s read and 598MB/s write speed, both averaged, while plugged into the Thunderbolt 3 port. Compared to the MacBook Pro’s nine seconds, it took the Blade Stealth 39 seconds to transfer the same 13GB file to the X5. This really highlights how much of a bottleneck the internal drive can be when working with an external drive as fast as this — it’s literally four times slower.

Samsung T5 1TB SSD

While the X5 is Samsung’s flagship external drive, the Samsung T5 line is more accessibly priced at around $180 for a 1TB model. The T5 is more of an everyday drive for those that need fast file transfers, but aren’t planning to use it as a scratch drive for video editing. At less than half the price of the X5, its performance is impressive — plus, I prefer its slim, money clip-like design to the X5’s sporty styling.

This drive utilizes SATA storage with a USB 3.1 Gen 2 interface, and since both test machines used in this article feature Thunderbolt 3 ports, the drive’s speed won’t be negatively impacted by the interface. The T5’s interface makes it compatible with a broader array of devices, too: you can use this on both macOS and Windows 10 computers, but also with Android phones. I ran all of the tests with its USB-C to USB-C cable, but it also includes a USB-C to USB-A cable in the box for use with older computers.

Samsung claims that this little drive can reach speeds of 540MB/s for both reading and writing data. My results were fairly close to these claims on both test machines. Using the same benchmarks as before, the T5 registered a 518MB/s average read and 475MB/s write on the MacBook Pro, and an average of 508MB/s read and 487MB/s write on the Blade Stealth.

Transferring a 13GB file from the MacBook Pro to the T5 took an average of 29 seconds, about three times slower than with the Thunderbolt 3 X5. It took 33 seconds on average to perform the same transfer when connected to the Razer Blade Stealth. It’s not clear why the T5 outperformed the X5 on the Stealth, but it does highlight how paying for the faster external drive just isn’t worth it if your computer doesn’t have a fast enough internal drive to keep up with it.

Intel 660p 1TB NVMe M.2 SSD

While the X5 and T5 are pre-built and ready to go right out of the box, building your own external drive using an M.2 NVMe SSD and an enclosure can produce some surprising results. I tested out Intel’s 660p M.2 NVMe PCIe 1TB SSD (currently $110) with an enclosure, which has a few perks over the Samsung T5: it’s a bit cheaper, faster, and lastly, it’s a fun little project to put one of these together.

There are a couple of different types of drives in the M.2 format (which refers to the drive’s physical size), and you’ll want to make sure you’re buying an NVMe PCIe drive, not a SATA-based one. Maximum transfer speeds can vary even among NVMe drives, but if your goal is to use it as an external drive, you don’t need to buy the fastest ones available because you won’t be able to use all of their bandwidth. The 660p drive that we tested is rated at 1,800MB/s for both read and write speeds, which isn’t the fastest you can get but is fast enough to saturate a USB 3.1 Gen 2 connection. Faster NVMe drives, such as Samsung’s popular 970 EVO Plus, cost a lot more money and you won’t get any benefit from using them in a USB 3.1 external enclosure.

Even though they are still relatively new, there are plenty of NVMe enclosures to choose from. The two that I tried out come from Plugable (currently $49) and ElecGear (currently $45). Both are compatible with NVMe PCIe SSDs and each supports the USB 3.1 Gen 2 standard. Depending on the enclosure that you purchase, the total cost is around $160. That’s less than the Samsung T5 costs, and thanks to the 660p’s fast read and write speeds, it’ll outperform it as well. Thunderbolt 3 enclosures, which do have the potential to take advantage of the fastest NVMe drives, are just now starting to hit the market, but they are significantly more expensive than USB 3.1 Gen 2 models. If you want Thunderbolt 3, you should just go with a pre-built drive like the Samsung X5 at this point.

Installing the SSD in an enclosure is simple: open the enclosure (Plugable’s tool-less design makes this incredibly easy; other enclosures will require opening a few screws), align the pins, and secure the drive to keep it in place. Since external SSD drives can generate a lot of heat, it’s advised that you install thermal pads to help keep temperatures down in use. Both enclosures I tested include these pads in the box.

Getting this DIY drive up and running on your computer is a little different than the others that I tested. It’s still a plug-and-play affair on macOS, but Windows 10 won’t recognize this drive once connected; you’ll have to install a partition on it and assign it a drive letter in the Disk Management setting before it can be used like a portable drive. Once you’re done with that, it works just like the T5 and is compatible with the same broad array of USB-C and USB-A ports.

The results from the MacBook Pro and Razer Blade Stealth are mostly at parity with this drive. Using the Blackmagic Design disk benchmark, I got an average of 933MB/s read, 910MB/s write on the macOS laptop, while Razer’s put up slightly faster numbers with the Novabench and ATTO benchmark tools: 961MB/s read, 942MB/s write, on average.

Regarding the file transfer speed, this DIY NVMe drive shows decent improvements over Samsung’s similarly priced T5 SSD. On macOS, I saw an average of 17 seconds for the 13GB file transfer, a roughly 41 percent improvement over the T5’s time. It took an average of 29 seconds to transfer the same file from the Razer laptop to the drive (that’s four seconds faster than the T5, and a whole 10 seconds faster than the X5).

Which one should you buy?

If you’re looking for the absolute maximum data transfer speeds in a portable drive and know that your computer has the right port and fast enough internal storage to keep up with it, Samsung’s $450 X5 Thunderbolt 3 SSD is the best pick. It’s over twice as expensive as the other options, but it’s also over twice as fast, which can make a noticeable difference if you’re working with a lot of huge files.

But if you’re not a professional video editor and you’re just looking for a small, fast portable drive for files or photo library storage, I recommend going with an NVMe PCIe SSD and an enclosure. Setting it up isn’t as daunting as it might seem, and not only is it a better value in terms of performance than the Samsung T5 and the Samsung X5, you can also pop the SSD into a compatible desktop motherboard if you decide to retire it from the portable life.

Buy Samsung’s X5 Thunderbolt 3 SSD: Amazon | Best Buy | Google Shopping

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