MacworldAt a glanceExpert's RatingProsSuper fast 6GBps reading, 5GBps writing via Thunderbolt 5Rugged and weatherproofHandsome designA bargain compared to Apple internal SSD upgradesConsExpensive compared to Thunderbolt 3/USBRequires an M4 Pro/Max Mac for full 80Gbps performanceLimited compatibility with older hardware and software.Our Verdict We love that the new Envoy Ultra Thunderbolt 5 SSD from OWC is almost as fast as Apples internal storage, but its not cheap and backwards compatibility isnt all-encompassing.Price When ReviewedThis value will show the geolocated pricing text for product undefinedBest Pricing TodayIf youre looking to take full advantage of the Thunderbolt 5 ports on your M4 Pro Mac mini or M4 Pro/Max MacBook Pro and possibly circumvent Apples avaricious storage upgrade pricing, you should consider OWCs Envoy Ultra Thunderbolt 5 external SSD. The Envoy Ultra is hardly cheap, but its nowhere near what Apple charges.On the downside, there are more backwards compatibility issues than expected.This is the compatibility statement from the Thunderbolt 5 PR deck. Broadly apparently doesnt mean Completely. Especially with older software and hardware. Thunderbolt 5 compatibilityWhile the speed is alluring, and Thunderbolt 5 itself is backwards compatible with older Thunderbolt specs, its not nearly as backwards compatible as you might think, we wish, or is hinted at.First, you need a Thunderbolt 5-enabled Mac or Windows PC to take full advantage of Thunderbolt 5s 80Gbps transfer rates. 80Gbps? Yes. While you may have seen 120GBps quoted in some articles as Thunderbolt 5s top speed, thats only unidirectional for displays. Bi-directional, as with storage, is limited to 80Gbps.The first compatibility issue is that to utilize a Thunderbolt 5 drive, Apple silicon Macs need either macOS 14 Sonoma, or macOS 15 Sequoia. Thunderbolt 3 Macs with Intel chips must run Sequoia. Note that the Envoy Ultra did enumerate on my Mac Studio Thunderbolt 4 bus when I was back on Ventura, but it wasnt available in Disk Utility or Finder.Also, while the Envoy Ultras captive cable prevents me from testing it on older Thunderbolt 1/2 using an adapter, the image above indicates that this is off the table. OWC confirmed that Thunderbolt 5 wont work with the older standards, so stick with Thunderbolt 3 equipment for older Macs.OWCs Envoy Ultra Thunderbolt 5SSD.Jon L. JacobiAdditionally, in my testing for PCWorld, there was a rather large issue with the official test bed. That issue is that the Envoy Ultra completely failed to register in the BIOS, Disk Manager, or Thunderbolt utility. Oops. This is despite updating all the drivers, removing everything non-essential, and even updating Windows 11 to the latest release on the test bed. Eventually, a BIOS/Thunderbolt firmware update from Asus solved the issue.This iffy backwards compatibility could be a problem if youre working in a mixed operating system environment. Some older equipment might not be updated.FeaturesThe OWC Envoy Ultra shares the handsome, sculpted styling of the Thunderbolt 3 40Gbps/USB 3.2 10Gbps Envoy Pro FX. However, its a bit larger chunk of black metal, measuring about 0.75 inches thick, 2.8 inches wide, and 5 inches long. The Envoy Ultra weighs in at a satisfyingly substantial 10.5 ounces or so.The OWC Envoy Ultra attached to the MacBook Pro M4 Pro used for testing.I already mentioned the captive cable, which is for weatherproofing (its not IP-rated, but it seems as if it could pass the tests) and making sure you cant lose it. It does, however, make it a bit harder to stow the Envoy Ultra in tight quarters. Also, as with all captive cables, you should avoid stressing the attachment point for longevitys sake.The OWC Envoy Ultra carries a three-year warranty, but no TBW (Terabytes that may be Written) rating was given.PriceIf you thought a Thunderbolt 5 SSD was going to be cheap.well, I have some interesting real estate properties you might be interested in. The Envoy Ultra costs a cool $400 in its 2TB form and $600 at 4TB.Given that you can grab a Thunderbolt 3/USB4 SSD for roughly half that, and a 20/10Gbps unit for far less than half, youd better really need or want the speed. Note however, that despite a new 20Gbps 3.22 tunneling protocol that may work with docking stations, 3.22 SSDs still drop to 10Gbps when attached directly to a Thunderbolt 5 port. 20Gbps USB4 SSDs will operate at full speed attached to Thunderbolt 5.Then again, compared with Apples egregious price gouging for internal storage upgrades ($1,200 for 4TB???), the Envoy Ultra is a fantastic bargain.PerformanceShort answer: Very fast. Benchmarks showed anywhere from 5.2GBps (Blackmagicdesigns Disk Speed Test), to 6.5GBps reading (AmorphousDiskMark), to near 7GBps reading and 5.57GBps writing (ATTO). Even my real-world read of approximately 330GB of .mov files showed an excellent turn of formalmost 6GBps reading. Alas, writing was considerably slower, only around 1.5GBps.Note I copied to and from the same M4 Pro MacBook Pro (2TB) that I ran the synthetic benchmarks on. By way of comparison, and for the enlightenment of those who might be looking to avoid paying ridiculous sums for Apples internal storage, I included the benchmark results from the MacBooks internal SSD. These are shown to the right of the OWC Envoy Ultras in the images below.The difference between the internal and external storage isnt as severe as you might expect. Long story short, read results are remarkably close for the most part, though the internal SSD was a good deal faster writing under nearly all circumstances. Note that the fastest external SSD weve previously tested, the USB4 Adata SE920 only just exceeded 3GBps reading. YesVery fast.Blackmagicdesigns Disk Speed test showed consistent 5.2GBps performance in both reading and writing for the OWC Envoy Ultra (left). The Internal M4 Pro MacBook Pro SSD results are shown on the right.AmorphousDiskMark showed better numbers for the Envoy Ultra readinga rather scintillating 6.44GBps. Not that far off the MacBook Pro M4 Pros internal SSD. Approximately 5GBps writing from the Envoy Ultra seems to be the consensus from all three synthetic benchmarks.AmorphousDiskMark showed the Envoy Ultra reading far faster than Disk Speed test. Nearly 6.5GBps. ATTO Disk Benchmark paints largely the same picture, though read speeds for the Envoy Ultra actually exceeded those of the MacBook Pro M4 Pros internal SSD. Writes? No, though around 5GBps is hardly anything to sneeze at. ATTO Disk Benchmark paints largely the same picture, though read speeds for the Envoy Ultra actually exceeded those of the MacBook Pro M4 Pros internal SSD. Writes? No, though around 5GBps is hardly anything to sneeze at. Although our real-world file writes didnt match the benchmarks, they were still quite good. In total, the OWC Envoy Ultra is a very nice upgrade performance-wise from the average Thunderbolt 3 SSD, and a worthy companion for any Thunderbolt 5 Mac.Note that the SSD inside the Envoy Ultra is the Auro Pro IV. You can read more about its performance (good at the time, not so much now) in sister publication PCWorlds review. That said, the Envoy Ultra, once running on our updated test bed, turned in a very, very slow 450GB write time.Should you buy the OWC Envoy Ultra?If you want, and can afford the absolute fastest storage for your new Thunderbolt 5 Mac, then the answer is yes. Have at it. Also, its a heck of a lot cheaper than Apples rapaciously priced internal storage and nearly as fast. That said, Thunderbolt 3/USB4 SSDs are still plenty fast, cheaper, and far more compatible with older Mac hardware and software. Ill leave the value equation up to you.