Is USB or Thunderbolt better for portable SSDs? The key differences, explained

I could spoil this entire article and tell you right off the bat which high-speed bus protocol you should be looking at for you current and future external storage needs… But where’s the fun in that?

If you need an answer right away, simply scroll to the bottom and grab your instant gratification. Otherwise, educate yourself with this quick treatise on the various high-speed external protocols that are available, as well as their respective strengths and weaknesses.

10Gbps USB (USB 3.2)

So, have we really come so far that a 10Gbps/1GBps transfer rate seems quaint? I’d say, yes, at least from the perspective of a long-time storage reviewer. Nevertheless, for small amounts of data, a 1GBps transfers rate is still going to get the job done quickly enough.

Jon L. Jacobi

And, of course, for a lot less cash than the 20Gbps/40Gbps options. If capacity means more to you than top performance, then 10Gbps USB (or even 5Gbps if you really don’t care about speed) could be the way to go.

Best Usb 3.2 external drive

Crucial X9 Pro

Read our review

Price When Reviewed: 99,99 Euro

Best Prices Today: 100,00 € at notebooksbilliger | 102,50 € at tease-Shop | 104,62 € at Amazon Marketplace CE

20Gbps USB (USB 3.2×2)

This protocol offers fast 20Gbps transfers, but it’s the odd duck of the bunch. It will work on normal USB ports at reduced 10Gbps/5Gbps speed, but a dedicated and not particularly common 3.2×2 port (sometimes referenced at 20Gbps) is required to attain the promised 2GBps transfers.

Another downside is that unlike USB4, USB 3.2×2 will not function at its full 20Gbps on most Thunderbolt 3 or 4 ports, instead dropping to 10Gbps — the rate of most native USB implementations. Thunderbolt passes through USB to the system.

That speed drop afflicts all new Apple Silicon Macs. I was sorely disappointed when I found out that my more-than-fast-enough 20Gbps USB SSDs transferred at half speed on my otherwise stellar-performing Mac Studio.

Jon L. Jacobi

On the plus side, 20Gbps USB SSDs run cooler, use less juice than their 40Gbps counterparts, and still gets things transferred pretty darn quickly. The price of USB 3.2×2 SSDs has dropped some recently, due to USB4 showing up, but they’re still not as affordable as a 10Gbps SSDs.

best usb 3.2×2 External drive

Lexar SL600 20Gbps USB SSD

Read our review

Price When Reviewed: 170 Euro

Best Prices Today: $129.99 at B & H Photo | 337,63 € at Proshop.de

Thunderbolt

While Thunderbolt has been the de facto high-speed port on Macs for well over a decade now, it’s not nearly as widespread on Windows PC platforms. Largely that’s because it’s pricier to implement than USB thanks to royalties and greater power delivery. That goes for both motherboards and drives.

Thunderbolt is certainly more common than it once was, but it’s hardly ubiquitous on the Windows side of the pond. Here are the various flavors you might run across.

Thunderbolt 1/2: These older versions with Mini-DisplayPort connectors and 10Gbps/20Gbps transfer rates are only found on legacy equipment, though you can connect newer Type-C Thunderbolt peripherals to these ports and vice versa using Apple’s Thunderbolt adapter. There are others, but check the specs carefully — some don’t connect 1/2 to 3/4/5, only vice versa.

My advice? Stick with newer Thunderbolt 3/4/5 peripherals and use the adapter. Or perhaps upgrade your computer.