The new Segate FireCuda X Vault and One Touch got rid of a external power supply and takes power directly from host via standard USB-C and the influencers are hyping it like it’s a good thing.
I got extremely confused. External SSDs can get away with host powered because they consume much less power. But external HDDs are externally powered for a reason. There’s literally spinning discs in there!
Per FireCuda X Vault’s FAQ or One Touch’s FAQ:
Problem: The device is unavailable
Q: Is the LED flashing red?
A: The device is unavailable because the host computer is not providing a minimum 15 W of power. Connect the drive to a USB-C port that delivers 15 W of power or more.
So this means that it needs a standard 5V3A power output from the host USB-C port.
Thunderbolts and USB4s are fine
Let’s first get one thing out of the way: Thunderbolts and USB4s will do fine.
Per USB-IF’s standard USB4™ Thunderbolt 3™ Compatibility Requirements Specification, in 4.1 Host Source Power Provisioning:
A USB4 Host shall support Host Power provisioning as defined in the USB PD Specification. If a USB4 Host has one USB4 Port, it shall provide at least 15W of power after Thunderbolt Alternate Mode is entered.
The doc I linked is about how USB4 is built on TB3 but since TB4 is built on USB4 and USB4v2 is built on USB4 and TB5 is built on USB4v2. This means all TB3, TB4, TB5, USB4, USB4v2 ports should all be able to output 15W.
Additionally, as of now, all host ports claiming to be USB4v2 are actually all using a TB5 host controller chip(JHL9580) because there’s no widely compatible and massively available USB4v2 host controller chip available yet unlike the case with USB4 with ASM4242. Since Intel TB chips have long been the golden models, these ports should all be up to the task.
Tangent: the corresponding device chip of JHL9580 is JHL9480 and that of ASM4242 is ASM2464PD/ASM2464PDX.
USB 3 and USB 2 troubles
However, on the other hand, when we look at regular 10 Gbps, 5 Gbps, 480 Mbps USB, things are different. (NO i will NOT call them USB 3.2 gen 2 blablabla etc, but just in case you don’t know: USB 3.2 Gen 2 = 10 Gbps, USB 3.2 Gen 1 = 5 Gbps, USB 2.0 = 480 Mbps)
Let’s first look at the standards. Per USB Type-C® Cable and Connector Specification, in 4.6.2.1 USB Type-C Current:
The USB Type-C connector uses CC pins for configuration including an ability for a Source to advertise to its port partner (Sink) the amount of current it shall supply:
- Default is the as-configured for high-power operation current value as defined by the USB Specification (500 mA for USB 2.0 ports; 900 mA or 1,500 mA for USB 3.2 ports in single-lane or dual-lane operation, respectively).
- 1.5 A.
- 3.0 A.
What this means is that, for USB 480 Mbps, its minimum wattage is 2.5W, and for both USB 5 Gbps and USB 10 Gbps, their minimum wattage is 4.5W.
Side note: This also says dual-lane, which is USB 3.2 Gen 2x2 a.k.a. USB 20 Gbps, should do at least 9W, but very few people care about this speed including me (not to be confused with USB4 20 Gbps which is single lane! but even less people care about this speed)
So from the strictly standards standpoints, neither USB 3 or USB 2 will guarantee usability of Segate FireCuda X Vault, which requires 10W+ of the mandated floor watts of them.
Now notice how there are also 1.5 A and 3.0 A listed in the standards. That means the manufacturers are well within their rights to bump the power up to 7.5W or 15W if they see fit, but is under zero obligation to do so.
What makes matter worse is that laptops marketing don’t usually tell you the power output capability of these ports. They usually simply mark the speed because that’s what most people care about. Although from my biased experience most premium laptops mostly opted to do the full 15W on all their ports.
Macbook Neo
Allow me to be a devil’s somewhat advocate and ignore gaming laptops and pick Macbook Neo as an case example. On its Apple’s official tech specs page, in Charging and Expansion, it only says:
- One USB 3 (USB-C) port with support for:
- Charging
- DisplayPort
- USB 3 (up to 10Gb/s)
- One USB 2 (USB-C) port with support for:
- Charging
- USB 2 (up to 480Mb/s)
- 3.5 mm headphone jack
But on reddit there is a user report that says the USB 3 port only output ~6.7W. That would suggest it’s probably doing 5V1.5A, and I think it’s safe to assume that the USB 2 port can only output the same or less. If this deduction is sound, the Macbook Neo would then NOT be compatible with either the Segate FireCuda X Vault or Segate One Touch, which would be a huge hidden gotcha in my opinion.
Remedy?
An immediate remedy for cases like this would be to use a USB-C power/data Y-splitter. However, from my experience with having at least 3 broken splitter when using them for my two JetKVM, I don’t think they’re very reliable. I recently purchased a dedicated USB-C power/data splitter board but I haven’t had enough time to validate long term reliability. In addition, having an external splitter and an extra external power source kinda defeats the whole purpose of these two Seagate drives.
A safer remedy would be an externally powered USB hub. These come by very cheap and they come in plenty. They can solve the entire power problem with these drives on top of giving you more data ports and more power head rooms for other devices, but again I feel like this still kinda defeats the purpose.
Conclusion
I think what Seagate should’ve done is put an extra power port on them, be it USB-C or DC barrel jack, so when people’s hosts cannot supply enough power they can be externally powered, and when hosts can supply enough power they just takes power from the hosts, but then that might confuse people and ultimately Seagate cannot market them as a “single cable” external HDD, which is probably what they want to highlight the most in the first place anyway.
Honestly I applaud Seagate for trying to innovate in this otherwise quagmire market of external HDDs, but the hype got me worried about the eventual disappointment people gonna have when they realize their device is not compatible with them.
I personally own two 24 TB Seagate Expansion Desktop and I think the size of their power supply are quite small and doesn’t feel cumbersome. I’m not really sure who these two new external HDDs are for either. Price hike aside, if you’re traveling a lot and why not just get some 8 TB external SSDs?