USB 3.0 or USB 3.1 or Thunderbolt 2 for external spinning disks …?

I recently replaced my failing BlackX external drive enclosure with an Insignia from Best Buy. Needed something same-day, and it was in stock.

Now I’m revisiting a recommendation I received on this forum:

The Insigina is USB 3.0. The lower-priced OWC is USB 3.1. The higher-priced OWC is Thunderbolt 2.

Given the fact that the box on the one from Best Buy was pretty ragged and had none of the original packaging (sold as “new”), I’m questioning whether I even want to keep it - but it’s propping me up temporarily.

If I did keep it, it’s USB 3.0. Which by my understanding is 5 Gbps. The cheaper one from OWC is USB 3.1, which is double that. And the more expensive OWC one is Thunderbolt 2, which is quadruple that.

But for the average external hard drive, any of those speeds should be faster than the drive, even if it was an SSD….correct?

And if so, is there a reason I’d benefit from USB 3.1 or Thunderbolt?

I realize that the OWC product will almost certainly be more reliable, and will actually be new when I purchase it. But I’m wondering why the Thunderbolt version costs almost twice as much.

Any insight?

There’s the issue of speed – yes, USB 3.1 has a much larger pipe than USB 3.0, and no, a 3.5" spinning hard drive will not saturate either pipe, though an SSD will benefit from 3.1 vs. 3.0.

But there’s another angle, which you touch on: reliability. Even though I’ve had some issues with OWC, I have had a lot more of my purchases from them be trouble-free.

One of things OWC has (they bought it) is the software RAID program SoftRAID. I use it for a lot of data storage, and it has been a good, reliable solution in part because its support is so good.

A relevant example. A few years ago I wanted to setup a back up RAID using two Mediasonic ProBox – 4 bay HDD enclosures – with SoftRAID and some older drives.

But I thought; why not ask for advice from the vendor. I wrote in part:

I was thinking of putting [my old drives] in (2) USB 3.1 enclosures (perhaps like the OWC ones) and striping all the disks with RAID 5.

I have been doing this with Thunderbolt 2 / 3 with no real problems. My question: is the USB 3.1 protocol robust enough to support this use?

The response I got was from an author of SoftRAID who regularly troubleshoots drive I/O issues on the most basic level.

Most of the time, it is.
the problems I see are:
USB is very slow, with RAID you won’t get more than probably 200MB/s over USB 3.
USB sometimes does weird things, causing volume corruption, more often than the normal HFS issues with volume directories.

I would stick to Thunderbolt as much as possible.

Now, this use case was for RAID, and not just vanilla disk use. I think USB 3.0 or 3.1 is just fine for typical uses. But thunderbolt shines with more complicated I/O scenarios.

From their support forums:

Thunderbolt is both faster and more reliable than USB. In Mac OS in particular, there are USB issues that allow corrupted memory to be written to the protected area of a disk, damaging the volume.

USB is much slower with any RAID especially RAID 5 (40-50% slower).

I would not consider USB for anything but casual backups, not for serious data storage.

So a long story short: USB 3.0 is fine, I would spring for 3.1, but I prefer, when possible or practical, TB2/3.

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I recently heard someone on a podcast discussing drive age and got to wondering about my external media drive (1TB) and TimeMachine drive (2TB) - turns out they were 7 and 8 years old. Yikes!

After a lot of pricing and laying things out in spreadsheets, I realized that my ideal setup was probably a drive dock that would hold 2.5" drives and would allow for future upgrade to SSD. Unfortunately finding said dock proved impossible with sources currently available to me here in Mexico. I was also very surprised that SSD prices had not come down more. In the end I settled on a 2TB and 4TB external 2.5 spinning drives from Seagate. As a bonus, they both came with free Mylio accounts. Since I already had a membership, I am receiving extensions. I should receive a free year, which knocks the net price of the two drives down below $200US.

After formatting and copying the old drives are now just backups. The new drives, even though they are only USB 3.0 (I think) are still showing around 80-100% faster read/write transfer speeds. For my next upgrade in 3-4 years, hopefully SSD is more reasonable, and hopefully I’ve been able to source a dock by then.


Drive docks were a lot more popular a decade+ ago, when some people purchased bare drives because they were $100 or more cheaper than external drives. But these days the price differences can be negligible, and failure of a drive dock can be more problematic than losing a single external drive (which presumably has a backup or is a backup).

I think drive docks can be a temporary solution, or a good tool for techs who need to access drives pulled from computers, but they often have problems with robustness over long periods.

I recently pointed to a BackBlaze report of their drive usage which found annual failure rates averaging 12% by Year 4. I individually ID my drives and set reminders in my task manager to replace my drives every five years.