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lcubed

macrumors 6502a
Nov 19, 2020
540
326
Just as a final update...

So I purchased a new USB-C to DisplayPort 1.4 cable from Amazon - brand name "uni" and supports 8K@60Hz, 4K@120Hz, 2K@240Hz, 5K@120Hz, HRD, HBR3, HDR10, ARC, 32.4Gbps, FreeSync, G-Sync, MST, DSC. This cable was recommended in a forum as being compatible with the Mac Studio for connecting to a 4K DisplayPort monitor.

After running this setup for 2 weeks now I am pleased to report zero issues with the attached TB drives and the display being connected simultaneously. But initially even the "uni" cable did not work until I plugged-in the USB-C plug reversely, even though this should not matter with USB-C. It seems the Mac Studio has some rather funky UB-C ports - as also some USB-C cable plugs fit only loosely while others again are hard to plug-in. And it's definitively rather selective about which USB-C cables it will agree to work with.

sounds like a USB-C manufacturing spec issue if some fit and others don't.
 

brandair

macrumors member
Sep 6, 2010
88
38
Unfortunately, I must revoke my positive assessment. The spontaneous disconnection of my Acasis TB405 enclosures with raided WD Black SSD's happened again multiple times as of today. Last week I had one single disconnection. In both cases it happened after exporting images from Capture One to the external raid. Take note that C1 utilizes the GPU to great extend. But now even without using C1 I get constant disconnects when writing to the raid.

As a temporary measure, I removed the USB-C to DisplayPort 1.4 cable and replaced it with a HDMI 2.1 cable. No more raid disconnections.

I can only conclude that this is a Thunderbolt controller issue with the Mac Studio. Saturating both TB data channels and the 8Gbps DisplayPort channel at the same time apparently will crash the TB data channels. In any case, that's a rather annoying bug and limits the output options!
 

xavierf62

macrumors newbie
Oct 13, 2023
2
1
Hi,
I resolved the problem with 2 acasis TB405 thunderbolt connected to mac studio M2 Max who use USB instead thunderbolt,
I bought a powered thunderbolt dock Satechi, and now the 2 thunderbolt enclosure connects in thunderbolt PCI express ✌️ I think the thunderbolt port on mac studio are under powered and cannot send sufficient power to the enclosure, with powered dock, it s good.
 

bigplume

macrumors newbie
Original poster
Apr 1, 2022
16
3
Hi,
I resolved the problem with 2 acasis TB405 thunderbolt connected to mac studio M2 Max who use USB instead thunderbolt,
I bought a powered thunderbolt dock Satechi, and now the 2 thunderbolt enclosure connects in thunderbolt PCI express ✌️ I think the thunderbolt port on mac studio are under powered and cannot send sufficient power to the enclosure, with powered dock, it s good.
Hi, I just meet the same problem, but by connection two enclosure to a dock station, they share the one port on the Mac Studio, does the speed be limited?
 

p_rousseau_fr75

macrumors newbie
Apr 8, 2024
2
0
Hi,
I'm a Mac Studio M2 Max user and I plan to get a Acasis TB405 as a secondary drive because my internal drive is almost full.
Do you know if the Mac Studio M2 Max has the same TB controller issue as M1 Max? If so, I might get the same problem as described above because my two monitors are connected via tb ports already.
Maybe I should consider getting a powered enclosure instead. Can anyone recommend something similar to TB405?
 

bigplume

macrumors newbie
Original poster
Apr 1, 2022
16
3
Hi,
I'm a Mac Studio M2 Max user and I plan to get a Acasis TB405 as a secondary drive because my internal drive is almost full.
Do you know if the Mac Studio M2 Max has the same TB controller issue as M1 Max? If so, I might get the same problem as described above because my two monitors are connected via tb ports already.
Maybe I should consider getting a powered enclosure instead. Can anyone recommend something similar to TB405?
I have no idea about M2 max TB controller. Here is a link for powered enclosure, it is actually a dock + enclosure, if you use is as enclosure only, the power supply is optional, but if you have problem of TB controller, then you can power the enclosure.
 
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xavierf62

macrumors newbie
Oct 13, 2023
2
1
Hi,
I'm a Mac Studio M2 Max user and I plan to get a Acasis TB405 as a secondary drive because my internal drive is almost full.
Do you know if the Mac Studio M2 Max has the same TB controller issue as M1 Max? If so, I might get the same problem as described above because my two monitors are connected via tb ports already.
Maybe I should consider getting a powered enclosure instead. Can anyone recommend something similar to TB405?
hi, i have a mac studio M2 MAX,
if i connect 2 TB405 directly on mac studio, only one is recognized as a thunderbolt, other connect as usb , the only solution i have found is connecting the two enclosures on thunderbolt powered HUB, i think there is no sufficient power delivered on thunderbolt port on mac studio to power 2 monitor + 2 TB SSD enclosurethe TB hub i use : https://satechi.net/products/thunderbolt-4-slim-hub
 
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Chancha

macrumors 68020
Mar 19, 2014
2,339
2,161
Check this past thread on the forum, the same behaviour was already reported ever since Apple Silicon was new.
It is indeed a power-wall issue. Apple designed their hardware with such limitation, for unknown reasons. And its effects and specific limits are undocumented.
 

p_rousseau_fr75

macrumors newbie
Apr 8, 2024
2
0
Check this past thread on the forum, the same behaviour was already reported ever since Apple Silicon was new.
It is indeed a power-wall issue. Apple designed their hardware with such limitation, for unknown reasons. And its effects and specific limits are undocumented.
Hi Chancha
Thanks for the link. I haven't read all the messages yet but a question arise.
My displays are:
- Apple Thunderbolt Display connected via TB2 to USB-C TB3 adapter
- Dell P2720D connected via DP to USB-C TB3 adapter
Both displays are plugged to a 220v wall outlet. Thus I suppose that they're not powered by the USB-C cable.
Does it change anything regarding the hardware limitation issue since it's a power-wall issue as you mention above?
 

Chancha

macrumors 68020
Mar 19, 2014
2,339
2,161
Hi Chancha
Thanks for the link. I haven't read all the messages yet but a question arise.
My displays are:
- Apple Thunderbolt Display connected via TB2 to USB-C TB3 adapter
- Dell P2720D connected via DP to USB-C TB3 adapter
Both displays are plugged to a 220v wall outlet. Thus I suppose that they're not powered by the USB-C cable.
Does it change anything regarding the hardware limitation issue since it's a power-wall issue as you mention above?
What I think will happen with your scenario is, if the displays are plugged in first and second, then the third device being plugged in is a bus-powered TB NVMe enclosure, macOS likely will show the “not enough power” warning. At this moment, you may have to unplug at least one of the displays and also the drive, plug the drive back, let it finish mounting then plug in the display last.

The linked thread had multiple users (including myself) reporting similar “solutions”. The core issue is macOS somehow seems to reserve a certain pool of power for each port’s connection regardless if it ends up being really bus-powered. That is, even after correct negotiation of your displays not needing power, macOS won’t release the reserve. Therefore the order of which these devices are plugged in matter.
 
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TzunamiOSX

macrumors 65816
Oct 4, 2009
1,057
435
Germany
I only read the first post until now

Mac Studio Max only has 4 TB ports on the back
Mac Studio Ultra has 4 TB ports on the back and 2 on front

EDIT: Ok, looks like an other problem.
 
Last edited:

Chancha

macrumors 68020
Mar 19, 2014
2,339
2,161
I did a further test on my Studio and MBP and was able to create 3 difference behaviour scenarios in terms of the order of plugging in:

M1 Max Mac Studio, Monterey

1) HDMI display
2) type-C display
3) TB4 + USB4 NVMe enclosure (mounts as TB)
4) TB3 NVMe enclosure (mounts as TB)

1) type-C display
2) type-C display
3) TB4 + USB4 NVMe enclosure (mounts as TB)
4) TB3 NVMe enclosure (does not mount, shows power warning)

1) type-C display
2) type-C display
3) TB3 NVMe enclosure (mounts as TB)
4) TB4 + USB4 NVMe enclosure (does not mount, no warning)

Of note is on a M1 Pro MBP 16" I managed similar results but with less devices, since one more is bus powered:

M1 Pro MBP 16", Ventura

1) type-C display
2) TB3 10GbE NIC
3) TB4 + USB4 NVMe enclosure (mounts as USB4 at 10Gbps)

1) type-C display
2) TB3 10GbE NIC
3) TB3 NVMe enclosure (does not mount, shows power warning)

The displays are identical and they al could show images in all tests, I just change the input from type-C to HDMI for the first test.
If I change the order and plug the displays last, none of the above problems show.

Bonus info:
I tried plugging in 3 TB bus-powered NVMe enclosures. The 3rd one absolutely does not mount until it is plugged via a powered dock first.
 
Last edited:

BrianBaughn

macrumors G3
Feb 13, 2011
9,849
2,506
Baltimore, Maryland
M1 Mac Studio Max: I just got two TBU405 Air enclosures directly from Acasis. These are the ones that are TB4 only…they won't connect or mount with anything less.

Well, I ran into this limitation. My LG monitor is connected to one of the TB4 ports and doesn't work on the front ports. I can only get one of the TBU405 Air devices to mount. Other, slower stuff connected to the fourth port works fine. Disconnecting the LG monitor allows the two TBU405 Air devices to mount. I don't have any other TB4 40gbps devices.

After some back and forth with Acasis I got this from them:

We have tested the Mac Studio M1 computer.
Mac Studio M1 has four Thunderbolt ports, but only the two Thunderbolt ports that are connected first can be allocated 40gbps, and the subsequent ones can only be allocated 10gbps.

You can try to see if the test results are the same as our test results. Apple's chips determine this and cannot be affected by our products.
This product does not consume much power.

So it would seem a powered TB4 hub is the next thing to try. I'm going to order the Kensington SD2600T:

 
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BrianBaughn

macrumors G3
Feb 13, 2011
9,849
2,506
Baltimore, Maryland
Further to this…I mentioned to the Acasis support person that I couldn't find any specific explanation of the TB limitation of the M1 Mac Studio on the internet. They replied:

We also are not been able to find a definitive explanation anywhere as to this limitation. However the test shows the limitation of the M1 Mac Studio computer is indeed.

I called Apple Support and the associate put me on hold while speaking to a senior technician. When she came back she said that two monitors connected to the rear might keep other devices from connecting at 40gbps but that only one monitor connected back there should allow all three of the remaining ports to connect at 40gbps. Then she suggested I take the computer to the Apple Store if it's not behaving in this way.

Maybe I will take it in at some point…but there's too many folks out there experiencing the limitation for me to think a store employee is going to figure this out. Here's an Apple DUC thread on the subject:


What you don't see is anyone claiming to have three or four ports all connecting at 40gbps.

My hub arrives next week and I'll post the results of that.
 

brandair

macrumors member
Sep 6, 2010
88
38
A TB hub is not the solution if you intend to run the two Acasis drives in RAID zero for more performance, since both would use the same TB port on the Mac Studio.

Acasis' answer is partially wrong as they are confusing the two front USB-C ports on the Mac Studio Max.

Alas, Apple's Thunderbolt implementation in at least all M1 and M2 products seems rather mediocre and buggy (power management). The four TB ports definitely only support two non-powered drives (directly attached) at most. And if a monitor is plugged in one of the TB ports, only one drive will mount as TB device, the other as USB 2.0! Also, there is the reduced write speed bug if no TB/USB-C monitor is plugged in (10Gbps bandwidth reserved for display). Certainly a downside of the M1/M2 architecture.



Further to this…I mentioned to the Acasis support person that I couldn't find any specific explanation of the TB limitation of the M1 Mac Studio on the internet. They replied:



I called Apple Support and the associate put me on hold while speaking to a senior technician. When she came back she said that two monitors connected to the rear might keep other devices from connecting at 40gbps but that only one monitor connected back there should allow all three of the remaining ports to connect at 40gbps. Then she suggested I take the computer to the Apple Store if it's not behaving in this way.

Maybe I will take it in at some point…but there's too many folks out there experiencing the limitation for me to think a store employee is going to figure this out. Here's an Apple DUC thread on the subject:


What you don't see is anyone claiming to have three or four ports all connecting at 40gbps.

My hub arrives next week and I'll post the results of that.
 

BrianBaughn

macrumors G3
Feb 13, 2011
9,849
2,506
Baltimore, Maryland
A TB hub is not the solution if you intend to run the two Acasis drives in RAID zero for more performance, since both would use the same TB port on the Mac Studio.

Acasis' answer is partially wrong as they are confusing the two front USB-C ports on the Mac Studio Max.

Alas, Apple's Thunderbolt implementation in at least all M1 and M2 products seems rather mediocre and buggy (power management). The four TB ports definitely only support two non-powered drives (directly attached) at most. And if a monitor is plugged in one of the TB ports, only one drive will mount as TB device, the other as USB 2.0! Also, there is the reduced write speed bug if no TB/USB-C monitor is plugged in (10Gbps bandwidth reserved for display). Certainly a downside of the M1/M2 architecture.
No plans for RAID.

I didn't read anything into the Acasis response as to the front ports.
 

BrianBaughn

macrumors G3
Feb 13, 2011
9,849
2,506
Baltimore, Maryland
The hub I mentioned in post #40 is working great. I can even plug my monitor into it alongside the two Acasis enclosures. I suppose that means I could plug another hub into one of the other three TB ports on the back and get 40gbps from even more stuff, if I had it.
 
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brandair

macrumors member
Sep 6, 2010
88
38
Sure, but all devices will have to share the 40Gbps bandwidth.

The hub I mentioned in post #40 is working great. I can even plug my monitor into it alongside the two Acasis enclosures. I suppose that means I could plug another hub into one of the other three TB ports on the back and get 40gbps from even more stuff, if I had it.
 
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