I write this tangentially HiFi related article in service of the Audiophile Style readership. I researched this for many hours and would like you guys to benefit from this research. Don't waste your time, waste mine :~)
A couple weeks ago the power in my house went out, and my QNAP TVS-872XT NAS went out with it. I replaced the power supply in the QNAP, but to no avail. The unit is now on its way to QNAP in Pomona, CA.
Without a NAS, I'm using a 16TB spinning hard drive that houses a backup copy of my 10.4 TB music library. Since switching to this spinning drive, I've been underwhelmed to say the least. Most underwhelming is the time it takes applications to start playing a track. If it's my first track of the day, it takes a while for the drive to spin up. If it's my hundredth track of the day it's OK, but can still be slow at times. In addition, when using an app like Roon that scans this drive at startup, I dread restarting the application because it takes longer than I feel like waiting.
What does any of this have to do with USB4.0? My impatience with slow performance got the best of me and I started researching faster USB drives to store my backup library. Given the price of high capacity solid state drives and the options for housing two 8 TB SSDs externally, among other things, I dialed back my expectations. I decided to look for a solution that could store part of my library. Due to the way I organize my music files, this is entirely possible without much pain, until my QNAP is returned.
I have my music files split into two directories, based on how frequently I listen to the music. On the 16 TB hard drive I have a folder named Current (2 TB) and a folder named Archive (10 TB). I started organizing my music this way because over the years I've used nearly every playback platform in high end audio, and I've learned that some don't work very well with 22,000 albums / 330,000 tracks / 10 TB. With two main directories I can point an application at only the Current music for indexing, if needed. It's this Current directory that I'd love to house on a very fast external USB drive, for times like these when my QNAP is out of commission.
The Current folder is 2.02 TB, which puts me in a position to either spend money on more storage than I need, or see if I can move more music into the Archive folder, and fit the Current stuff on a 2 TB NVMe drive. I opted for the 2 TB route and started researching the best external housings for NVMe drives. I like to purchase the drive separate from the housing, so I can easily swap one of the two out in the future if needed.
My Mac Mini (M1) has USB 4.0 ports and I like to purchase items that will last as long as possible. I figured a USB 4.0 drive will be viable much longer than a USB 2.0 drive and should also outlast a USB 3x drive. This is when my USB 4.0 research started.
A Little Background
The USB 4.0 spec was ratified by the USB Implementers Forum (USB-IF) on August 29, 2019. The big thing consumers will see with USB 4.0 marketing is support for 40 Gbps throughput. Please, do your best to ignore this theoretical maximum throughput speed because it will only cloud your judgement for now. Similar to how my 16 TB spinning USB drive has an actual capacity of 14 TB and a usable capacity of 12.7 TB after formatting, USB 4.0 won't get anywhere near 40 Gbps for the foreseeable future in real world conditions.
With that out of the way, let's look at the NVMe drives that go inside a USB 4.0 external housing. The current Samsung 980 Pro Gen4 NVMe SSD has a maximum read speed of 7 Gbps and write speed of 5.1 Gbps. This is a new drive using PCIe 4, not some old technology about to be upgraded. If the theoretical maximum speed of the NVMe SSD was reached, this would still leave 33 Gbps of headroom on a USB 4.0 connection. Learned computer audiophiles will also understand that hitting the top speed of an SSD required laboratory conditions using benchmarking tools designed to get the most out of a drive. In the real world, these speeds are never seen.
So, we have a USB 4.0 interface with a 40 Gbps theoretical maximum speed and the fastest drive with a theoretical maximum speed of less than 20% of that interface (7 Gbps). Still think it makes sense to pay the premium for a USB 4.0 drive? Keep reading.
There are three main external NVMe housings that tout USB 4.0 support, the Orico M2V01-C4, Yottamaster SO3-C4, and ACASIS TBU401. The fact that these external housings get away with saying USB 4.0 is beyond me, but let's just say it's bending the rules into a circle. Support for USB 4.0 in this case just means that the drive will work on a USB 4.0 port. If this is really the standard used for marking a USB 4.0 drive, then all USB 3.x drives could be called USB 4.0.
Getting away from the marketing side and looking at the actual capabilities of the chips inside these external housings tells the real story. All three housings use the JHL7440 Thunderbolt chip from Intel (The Yottamaster says it uses a nonexistent JHL440, but I believe this is a typo given the model numbers of Intel's Thunderbolt chips). The Orico and Yottamaster feature a separate USB chip, the JMicron JMS583. Let's look at each of these chips.
Intel JHL7440 - This is a Thunderbolt 3 controller with native USB 2.0, USB 3.2 Gen 1 (5 Gbs), USB3.2 Gen 2 (10 Gbs) support. No Thunderbolt 4 or USB 4.0 support in that it isn't in the spec, but will certainly work on those ports due to backward compatibility.
JMicron JMS583 - This is a USB 3.1 Gen 2 to PCIe Gen 3x2 / NVMe bridge controller. It's a fantastic USB 3 controller that can theoretically saturate the USB 3.1 Gen 3 10 Gbps bus, but it isn't a USB 4.0 controller.
Let's take a step back and look at the NVMe drives again. Note, both of these controllers support PCIe 3, not PCIe 4. The Samsung 980 Pro is a PCIe 4 device that works great on a PCIe 3 controller because of backward compatibility. However, don't worry about PCIe throughput limitations as the transfer speed to PCIe 3 is 8 GT/s and PCIe4 is 16 GT/s. I write this only to let people know that getting a drive that supports PCIe 4, just because it supports PCIe4, doesn't make much sense.
These USB 4.0 housings are also picky when it comes to NVMe drives. The ACASIS recommends the WD Black SN750, but not the faster WD Black SN850. It also recommends the Samsung 970 EVO, but not the Samsung 970 EVO Plus. The Yottamaster seems to work best with Samsung drives. It's as if the device was turned for these drives due to the better performance scores in a lab.
Back to HiFI for a second, I use this drive to store music and connect it to various music servers and computers. I like maximum compatibility when possible. The only one of the three main USB 4.0 housings that says it supports the older USB 2.0 standard is the ACASIS TBU401. The Orico M2V01 and Yottamaster SO3 don't support USB 2.0, even though the JHL7440 and JMS583 natively support it.
Wrapping It Up
All is not lost with these drives and USB 4.0 technology. These three drives are incredibly fast on paper and in some laboratory testing done by others. They seem to work great and outperform others spec'd at only USB 3.x GenX. However, don't be fooled by the USB 4.0 marketing. The drives's controllers don't physically support USB 4.0 speeds and included enhancements. it's a fact. Look at the specs and papers from Intel and JMicron.
I've yet to make a decision on what to do, but I highly doubt I'll purchase a "USB 4.0" housing anytime soon.
Orico M2V01-C4 ($180)
USB Controller - JMicron JMS583
Thunderbolt Controller - Intel JHL7440
Yottamaster SO3-C4 ($180)
USB Controller - Micron JMS583
Thunderbolt Controller - Intel JHL440 (However, this isn't a Thunderbolt chip part number according to Intel. My guess is this is a JHL7440)
ACASIS TBU401 ($140)
USB Controller - No separate USB Controller
Thunderbolt Controller - Intel JHL7440