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Studio Ultra - Simultaneous use of Bus Powered TB devices limited? (title edited)
- Thread starter Falcon_64
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It makes me wonder if the devices are complying with the power limits of the TB specification or if they are drawing a bit more than the spec allows for. If that’s the case, then what you’re seeing is device-related and not necessarily Studio-related.
I would still make a call to Apple support on this if for no other reason than to make them aware of the situation. They may be artificially limiting the available port power to keep the system cooler just as it appears they are limiting power to the M1 Ultra SOCs. If this is the case, they could possibly make an update that would allow for a little more headroom on power delivery to the ports.
I would still make a call to Apple support on this if for no other reason than to make them aware of the situation. They may be artificially limiting the available port power to keep the system cooler just as it appears they are limiting power to the M1 Ultra SOCs. If this is the case, they could possibly make an update that would allow for a little more headroom on power delivery to the ports.
These are my thunderbolt devices:
Dell 4k 32 inch display connected to rear TB port, Apple XDR Display connected to rear TB port, Cal digit TS3+ connected to rear TB port and Cal Digit Element connected to rear TB port. I use an OWC 4 hard drive thunderbolt enclosure but I only connect to move and save data but it becomes the 5th device. I use a OWC Envoy Express to copy over data and it connected by thunderbolt bus powered. So many times I have six connected devices thunderbolt.
I've run the 2019 Mc Pro and the Studio with two thunderbolt bus powered externals at the same time. OWC Envoy Express.
I kind of wonder if it isn’t just a firmware setting from the MacBook Pro. So many of the power settings for the Mac Studio are identical to the MBP, even when it shouldn’t be or makes no sense for them to be the same. Wonder if they just forgot to change some firmware notification setting from the 3 TB channels of the MBP to the 6 TB channels of the Mac Studio Ultra.
Physically speaking, the power supply in the Mac Studio should have no problem powering 6 TB devices at the same time. Moreover that is in the TB specification. So I really don’t think it is hardware limited.
I hear ya. If a device is drawing more power than spec permits, they should fail individually as well but they don't. Three bus powered TB devices = no problem. If that leaves insufficient power for a fourth TB device on a supposedly completely independent bus, that seems to indicate the 6 TB buses might be independent for data, but still be powered together.
@Adult80HD gets the same results as I do, but he's using different TB3 drives/enclosures than me. I find it unlikely that all our devices are drawing excessive power. More likely that there is an internal limit somewhere, intentional or not.
All this is conjecture. This is repeatable though (x2 anyway haha), and I troubleshoot systems that I'm not necessarily familiar with all day long so the patterns are important to me. and I have just enough experience with electricity/electronics to hurt someone (usually myself), in this case I know enough that this just seems more like a design compromise than anything else.
I'll still raise a ticket with Apple or hit up the Genius Bar. I'm confident the front line support teams won't have any idea about internal design but upper tier support folks might have access or be able to dig deep enough and be willing to share insight.
I just started a thread elsewhere about an M1 Max Studio as I didn't pick this up when searching. But, I get the same limitation on the M1 Max, but with there only being 4 Thunderbolt ports, I can't attach more ethanol 2 Bus powered Thunderbolt enclosures. So it certainly seems like 2 Buses are sharing power, which doesn't seem right to me - I assumed each was a full-on bus with power etc. I thought it might be as they are fairly budget enclosures, Acasis ones. Even with nothing else plugged into the Studio, only 2 drives will work at once.
With a 370 watt power supply, this is an odd limitation - but then again, I am not an Apple engineer.
The only solution is to place some of the bus powered drives behind a powered Thunderbolt hub, or chain it on with a different powered Thunderbolt device.
If I remember correctly, Intel Mac Mini's with 4 Thunderbolt ports, also exhibited some strange behavior like this when simultaneously using all four ports.
The only solution is to place some of the bus powered drives behind a powered Thunderbolt hub, or chain it on with a different powered Thunderbolt device.
If I remember correctly, Intel Mac Mini's with 4 Thunderbolt ports, also exhibited some strange behavior like this when simultaneously using all four ports.
@sfoxy, just posted on your thread, wanted to add the comment here as well in case someone is following this one.
I tested on my 14" M1 Pro and got the same result as you - only two bus powered TB devices at a time. With an M1 Pro/Max SoC able to provide power to 2 TB devices, I would expect an Ultra to handle 4 but nope.
I tested on my 14" M1 Pro and got the same result as you - only two bus powered TB devices at a time. With an M1 Pro/Max SoC able to provide power to 2 TB devices, I would expect an Ultra to handle 4 but nope.
We know that TB specs mandate 15W ceiling for each port but it is probably not how a number of TB ports sharing the same pool of power source works. It may just be a nominal average or a reference point.
For instance, the most power hungry NVMe SSD can draw 25W, that's not counting the additional TB controllers and some other chips on a bus-powered TB NVMe enclosure.
In macOS there is no wattage metering on ports that I know of, is there?
For instance, the most power hungry NVMe SSD can draw 25W, that's not counting the additional TB controllers and some other chips on a bus-powered TB NVMe enclosure.
In macOS there is no wattage metering on ports that I know of, is there?
I believe the 15W power for accessories is a minimum, not maximum, same as TB3. I don't know what the power draw is for the enclosures and NVMe sticks I'm using...so your point there could well be the cause. I haven't checked the SSD manufacturer for power requirements, I know the enclosures don't list anything like that.
I agree, that would be rather shocking. Good thing that's now what we are discussing here.
I have very occasionally had my 2018 Mac mini tell me that I'm drawing too much power from those ports and go on strike on one of them. As a practical matter, it hasn't been enough of an issue to look into it, but my recollection is that there's some power sharing going on with the mini ports. As I understand it, that's not supposed to be the case with the Mac Studio ports.
Did a quick check for the NVMe's I'm using (the tested numbers are from Tom's Hardware):
Samsung 980 Pro 2TB - max 7.2W (6.15 tested)
Sabrent Rocket 4 2TB - max 6.2W (7.38 tested)
WD Black SN750 2TB - max 6W (5.59 tested)
So that
I'm with you in that, now that it is known, I can work around this fairly easily. Finding out why there is this limit is a quest more than anything else, for me anyway. I won't speak for everyone. I find this type of knowledge useful for evaluating future promises and marketing claims on other new products, be they from Apple or any other manufacturer. Plus at work sometimes these oddball seemingly useless tidbits come in handy (I'm an IT consultant, go figure).
That's only for USB I believe. I certainly can't find that info for Thunderbolt.
I wonder why @albertjs says in this thread he was able to make a RAID 0 with four OWC Thunderblade 8TB SSDs on the Studio?
Could it be that the Thunderblade is better in this regard than other Thunderbolt SSDs? Anyone else with 4 Thunderblades able to test that?
(EDIT: Oh, because the Thunderblade is not bus powered. My mistake.)
Could it be that the Thunderblade is better in this regard than other Thunderbolt SSDs? Anyone else with 4 Thunderblades able to test that?
(EDIT: Oh, because the Thunderblade is not bus powered. My mistake.)
each OWC thunder blade uses an external power supply, so no worries regarding bus power.
I was recently on a chat with Apple and it was indicated that the amount of power delegated to devices is 100W, no spec was available as to the individual TB4 port(s). The envoy express (I have 2) draw is <10 plus the SSD which is a touch over 3 = 13.3 W. I have a shell thunder (unknown as to the enclosures power draw with fan) plus a similar ssd with 3.3W. The common denominator is the 3rd devices. The first device comes up (regardless of order), second device is good, third device has consistently given the lack of power message from Apple. I have ordered a 3rd Envoy to match up it all up to see if the #3 is the constant or other issue. Quite the pain that a device that is $2K can not have this figured out or at a minimum have a better troubleshooting mechanism. Apple support tried but had no specific spec as to the power output of the TB4 ports. I will provide an update once I try the 3rd Envoy....
An update, ordered another Envoy Express and again played with the order, the 3rd device is not getting power and no error message. This is either enough power getting to the connected devices or power distribution related. This is no longer a coincidence and a significant flaw somewhere in hardware and/or software. A little help here Apple......