Thunderbolt power? M1 Max - Anyone successfully using more than 2 External NVMe Enclosures?

[sfoxy]

The Mac Studio has 4 separate Thunderbolt buses, so I assumed that would mean each would have its own power delivery. However, I already have 2 external Thunderbolt 3 NVMe enclosures attached, and when I try to attach a 3rd, it says there is not enough power for it. I have unplugged everything else and tried just the 3 enclosures, but get the same. They are cheap Acasis enclosures, so wondered if that was the issue, or is it jus that the Thunderbolt buses share power? When I spoke to Acasis, that is what they claim, that 2 buses share power.

I know that was true on older Macs, but is it still true in the Studio? Or has anyone successfully running more than 2 Thunderbolt drives?

EDIT: Should have mentioned this is M1 Max.

 

[OldMike]

This was recently discussed here:

Studio Ultra - Simultaneous use of Bus Powered TB devices limited? (title edited)

Today I discovered that I cannot connect more then three thunderbolt drives (and the BenQ display using USBC) to my Studio Ultra. On the back four ports, I have connected: 1. BenQ SW321C 2. ProGrade TB3 CF Express card reader 3. & 4. Orico TB4 enclosure w/Samsung 980 Pro NVMe SSD If I connect...

forums.macrumors.com

 

[OldMike]

Just re-read the thread. From the following post:

Studio Ultra - Simultaneous use of Bus Powered TB devices limited? (title edited)

I just tested my Ultra today and got the same thing--you can't have more than three bus-powered TB drives attached. I used three Sabrent TB NVMe enclosures and one Acasis TB NVMe enclosure. When I go to add the fourth, I get the "not enough power" notice. I think it's the design. It should...

forums.macrumors.com

It seems that it is possible to get three bust powered drives running before receiving the low power message. I am using all of my ports, but only have the bus powered enclosures hanging off of enclosures that have their own power.

 

[sfoxy]

Just re-read the thread. From the following post:

Studio Ultra - Simultaneous use of Bus Powered TB devices limited? (title edited)

I just tested my Ultra today and got the same thing--you can't have more than three bus-powered TB drives attached. I used three Sabrent TB NVMe enclosures and one Acasis TB NVMe enclosure. When I go to add the fourth, I get the "not enough power" notice. I think it's the design. It should...

forums.macrumors.com

It seems that it is possible to get three bust powered drives running before receiving the low power message. I am using all of my ports, but only have the bus powered enclosures hanging off of enclosures that have their own power.

Ah, thanks for that. I did search for Thunderbolt in titles, but not TB!

 

[sfoxy]

Just re-read the thread. From the following post:

Studio Ultra - Simultaneous use of Bus Powered TB devices limited? (title edited)

I just tested my Ultra today and got the same thing--you can't have more than three bus-powered TB drives attached. I used three Sabrent TB NVMe enclosures and one Acasis TB NVMe enclosure. When I go to add the fourth, I get the "not enough power" notice. I think it's the design. It should...

forums.macrumors.com

It seems that it is possible to get three bust powered drives running before receiving the low power message. I am using all of my ports, but only have the bus powered enclosures hanging off of enclosures that have their own power.

I just clarified my original post that I have the M1 Max which only has 4 TB ports, so that is why I am limited to 2 bus powered drives. Seems that pairs of ports are sharing power. Acasis do a powered enclosure, so may have to get that.

 

[Falcon_64]

I just clarified my original post that I have the M1 Max which only has 4 TB ports, so that is why I am limited to 2 bus powered drives. Seems that pairs of ports are sharing power. Acasis do a powered enclosure, so may have to get that.

I'm the OP on the thread that @OldMike linked to. My Studio has the Ultra, that's why I'm getting one more than you are able to use with your Max. I think it's odd that, despite being two Max chips and double the TB4 ports, I don't get to use twice the number of bus powered TB devices.

After seeing your post, though, I tested on my 14" MBP. I have a M1 Pro, not Max, but TB4 ports are identical. Like you on your Max Studio, I only can use two bus powered TB externals, the third fails.