Though it was a bit rough around the edges in terms of backwards compatibility, my first look at 80Gbps Thunderbolt 5 storage reveals a very nice uptick in performance — about twice the 40Gbps of Thunderbolt 3/USB 4 in certain benchmarks. Logical.

By way of comparison, that’s roughly as fast as an NVMe SSD on the PCIe 4.0 bus. And a PCIe 4.0 NVMe SSD is exactly what’s inside the OWC Envoy Ultra portable drive I used to test Thunderbolt 5 storage.

Note that you’ll see 120Gbps listed in the Thunderbolt 5 specs, but that’s uni-directional output for driving multiple high-resolution displays. Bi-directional transfers such as those used by storage devices are “limited” to 80Gbps, or roughly 6- to 7GBps after overhead.

How well does Thunderbolt 5 work?

My debut look at Thunderbolt 5 came courtesy of the aforementioned Envoy Ultra attached to a Thunderbolt 5, 32GB Maingear ML-17 (Mk. II) laptop. Obviously, I wasn’t able to use the 59GB RAM disk in my standard test PC for 48GB transfers, but the T-Force NVMe SSD in the laptop provided a decently fast substitute.

Alas, the Envoy Ultra completely failed to appear on our official Asus ROG Strix Z790-I (Thunderbolt 4) test bed. It didn’t appear in the BIOS, disk manager, or the Thunderbolt utility. The issue is being cooperatively investigated by OWC, Intel, and Asus as the drive failed to enumerate on an Asus Maximus Z890 Hero board as well. In case you weren’t aware, Thunderbolt 5 is supposed to be full backward compatible with versions 3 and 4.

Further, only the newer Sonoma and Sequoia versions of macOS would recognize the Envoy Ultra for use on my Apple Silicon Mac Studio, though it was enumerated on the Thunderbolt bus in System Info as far back as Ventura. Sequoia is required for Intel-based Macs.

Finally, I was unable to test on older Thunderbolt 2 systems as the Envoy Ultra sports a captive Type-C cable which prevented me from employing Apple’s Thunderbolt 2 to 3 adapter.

This is an extremely small sample size of equipment, so I’m not sure just how pervasive the issues are, but there have been rumblings around the industry about the current state of compatibility. It’s definitely toe-in-water-time for Thunderbolt 5 — even for early adopters.

Note that after a Z790-I BIOS update (9901) provided by Asus on November 25th, 2024, the Envoy Ultra was recognized and performed as expected.

Further reading from another PCWorld expert: My first Thunderbolt 5 experience has been a massive bust

What Thunderbolt 5 gear is available?

Another Thunderbolt 5 laptop currently shipping is the Razer Blade 18. Both Asus and Gigabyte have announced a slew of motherboards that either feature Thunderbolt 5 or sport headers so they can be upgraded to it via add-on cards.

Can you upgrade older computers with add-on cards? According to my inquiries, no. There are some clever engineers and hackers out there, but there are timing issues and other factors that make porting backwards highly unlikely. Yup, you’ll need new stuff to get Thunderbolt 5 speeds. And note that neither Thunderbolt 4 or 5 are compatible with older Thunderbolt 2.

How about 6GBps sequential reading, and nearly 4GBps sequential writing with multiple queues? Then there’s nearly 4GBps sequential reading and writing single-queued. That’s a very nice bump up from the previous highs of around 3GBps multi-queued and 2.5GBps single-queued delivered by 40Gbps USB 4.

It’s about what we’d expect from doubling bandwidth from 40Gbps to 80Gbps. You can see the evidence below from CrystalDiskMark 8.

However, when it comes to random performance under CrystalDiskMark 8, the test picture painted no particular improvement. This stands to reason as increased throughput isn’t going to help any drive find/seek data faster.

To reiterate, this was a pre-production drive on a brand-new laptop rather than our official test bed. As I had to transfer my 48GB files from SSD to SSD I omitted those results. However, in total with this arrangement the Envoy Ultra still finished a mere second slower than the first place OWC 1M2 — easily within the margin of error for these tests.

We also omitted the results for our usual 450GB write as it’s more a test of the SSD inside and the amount of secondary cache it offers, rather than the speed of the bus. The Envoy Ultra was on pace for a stellar result if it hadn’t slowed to 1.2GBps when secondary cache was exhausted.

Again, official Envoy Ultra numbers will have to wait until we upgrade our test bed to Thunderbolt 5. The test results above are simply to illustrate the rough difference between Thunderbolt 3/4, USB 4, 10Gbps USB, and Thunderbolt 5 performance.

In summation, there was a marked increase in sequential transfers — with multiple queues and with only one. On suitably fast systems, it should save you time. Once again, random ops are minimally improved so don’t expect an uptick in lots-of-small-files scenarios.

Note that these tests were run on a pre-production version of the Envoy Ultra, though OWC did eventually get a shipping version to us.

What does Thunderbolt 5 mean for you?

Thunderbolt 5 is here and you probably want it (we do), even if it saves you only modest amounts of time in the real world. Time is money, of course, but to see a profit, you’ll have to overcome some hefty initial investments — the 2TB OWC Envoy Ultra I tested is $400 and the 4TB is $600. Gulp.

Thunderbolt 5 motherboards and Windows laptops are priced for the top-shelf as well, and the high cost-to-performance ratio carries over to the Mac. Only high-end newbies such as the Mac Mini (M4 Pro) offer Thunderbolt 5.

Long story short… For the nonce, Thunderbolt 5 is for adventurous early adopters, enthusiasts, and prosumers who actually need the speed, and have the software and hardware to take advantage of it. This is par for the course with any new technology, though we don’t remember these kind of compatibility issues with Thunderbolt 4.

Most folks will be just fine with less expensive and — at the moment — more trustworthy 40Gbps Thunderbolt 4 and USB 4, including our top-rated external drive, the Adata SE920.

Author: Jon L. Jacobi, Contributor, PCWorld