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Adapter to run 2 HDMI monitors from one TB port?
- Thread starter PianoPro
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This works great on my Surface Book so it should be fine for the Studio.
SABRENT Thunderbolt 3 to Dual HDMI 2.0 Adapter [Supports Up to Two 4K 60Hz Monitors on Mac and Some Windows Systems] (TH-W3H2)
The SABRENT Thunderbolt 3 Dual HDMI 2.0 Adapter (TH-W3H2) is the ideal device to add two HDMI monitors to your current workspace. The ability to increase one's work-flow by utilizing multiple monitors or displays is undeniable, and the Thunderbolt Adapter allows a person to do precisely that; mak...
www.amazon.com
This works great on my Surface Book so it should be fine for the Studio. Although the one I'm using is slightly different. This one is designed for Thunderbolt ports
SABRENT Thunderbolt 3 to Dual HDMI 2.0 Adapter [Supports Up to Two 4K 60Hz Monitors on Mac and Some Windows Systems] (TH-W3H2)
The SABRENT Thunderbolt 3 Dual HDMI 2.0 Adapter (TH-W3H2) is the ideal device to add two HDMI monitors to your current workspace. The ability to increase one's work-flow by utilizing multiple monitors or displays is undeniable, and the Thunderbolt Adapter allows a person to do precisely that; mak...www.amazon.com
Adapters similar to the Sabrent Thunderbolt 3 to Dual HDMI 2.0 Adapter do not use an MST hub to support two separate displays so they should work with macOS.
https://www.thunderbolttechnology.n...&field_prod_tb_version_value_many_to_one=tbv3
Just make sure whatever you choose is not using an MST hub internally.
Thanks. I want to run 3 HDMI monitors and I'd prefer to only use the one HDMI output and 1 TB output.
I see less expensive TB to 2 HDMI adapters that say they only produce the same display on 2 external monitors (and mention that's because Mac is not MST compatible) so that eliminates them. I suppose if they don't say there are incompatible then they are compatible, but that's always a dangerous kind of assumption. Guess I'll just buy the recommended Sabrent. Thanks again.
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I don't see how they could get less expensive - unless they are not actually Thunderbolt. Are you sure they are not just USB-C?
Yes, I think everything less expensive I've found are indeed USB-C to 2 HDMI adaptors. My confusion was that they were advertised to work with MacBook Pro's TB ports - but actually only produce the same display on 2 HDMI monitors.
So I bought the Sabrent TB 3 to Dual HDMI 2.0 Adapter you recommended. Thanks again for the info.
Wait, are we talking about the
The M1 Macbook only supports one external monitor, so it would end up just displaying the same thing on both external displays. The M1 Pro/Max support three external displays. Maybe that's where this idea that "Some dual TB to HDMI adapters only seem to produce the same display on two external monitors on the Mac but work on Windows" comes from.
No. You'll only see two displays with the same image if you have mirroring enabled (if you have a Mac that supports more than one display) or if the two displays are connected to an MST hub.
Most Thunderbolt to Dual HDMI adapters (those that use Thunderbolt and don't have any other ports) do not use an MST hub so they cannot and will not show the same image on two displays (unless mirroring is enabled and the Mac supports more than one display).
Amazon has a bunch of adapters advertised as USB-C to Dual HDMI in the $25-$35 range that produce the SAME image on 2 HDMI monitors from Mac's Thunderbolt ports, but 2 different images with Windows. Some specifically mention using MST (Multi-stream Transport) to deliver different images on multiple monitors with Windows, and I now understand Mac's do NOT support MST.
Example:
Selore&S-Global USB C to Dual HDMI Adapter 4K @60hz, Type C to HDMI Converter for MacBook Pro Air 2020/2019/2018,LenovoYoga 920/Thinkpad T480,Dell XPS 13/15/17,etc
USB-C to Dual Monitor Adapter | Windows | Thunderbolt 3 Compatible: This multi-stream transport hub solves that problem by enabling you to connect two separate displays to your USB-C computer, making multi-tasking much easier. Using this USB-C to HDMI video splitter, you can mirror your display o...
www.amazon.com
Apparently this is MacOS software issue, not a hardware issue, because (I read) that the same Mac TB ports will support MST running Windows via Boot Camp.
BUT the same Mac TB ports, DO support different images on adapters advertised as Thunderbolt to Dual HDMI with the M1 Pro and M1 Max (and presumably then the M1 Ultra in the Mac Studio). So that ability is apparently a Thunderbolt (not USB-C) feature that does not rely on MST?
But it does NOT work with the M1 Macs TB ports, so is that a hardware limitation of the M1 rather than a software issue?
Well I can tell you that on my M1 mini that only supports 2 displays, I had 3 displays connected, with one connected to the HDMI port and that same adapter connected to 2 other displays. The other 2 both had the same mirrored content displayed. I just assumed that the same would happen on the MacBook
Excellent example of a non-thunderbolt MST hub based adapter.Amazon has a bunch of adapters advertised as USB-C to Dual HDMI in the $25-$35 range that produce the SAME image on 2 HDMI monitors from Mac's Thunderbolt ports, but 2 different images with Windows. Some specifically mention using MST (Multi-stream Transport) to deliver different images on multiple monitors with Windows, and I now understand Mac's do NOT support MST.
Example:
Selore&S-Global USB C to Dual HDMI Adapter 4K @60hz, Type C to HDMI Converter for MacBook Pro Air 2020/2019/2018,LenovoYoga 920/Thinkpad T480,Dell XPS 13/15/17,etc
USB-C to Dual Monitor Adapter | Windows | Thunderbolt 3 Compatible: This multi-stream transport hub solves that problem by enabling you to connect two separate displays to your USB-C computer, making multi-tasking much easier. Using this USB-C to HDMI video splitter, you can mirror your display o...www.amazon.com
True. And sad. macOS can use MST hubs for converting DisplayPort signals. For example, from fast/narrow (HBR3 x2 with DSC) to slow/wide (HBR2 x4 without DSC or with DSC pass thru).
Correct. The Thunderbolt controller in the host takes two totally seperate DisplayPort connections (4 lanes each) from the GPU, converts the DisplayPort data to Thunderbolt packets, sends them to the Thunderbolt controller in the dock or hub or adapter (or old Thunderbolt 1 iMac in the case of Thunderbolt Target Display Mode), which converts the signals back to DisplayPort.
MST is a DisplayPort connection with multiple DisplayPort streams. Thunderbolt is a Thunderbolt connection with multiple tunnelled DisplayPort connections which could each include multiple MST streams.
Correct (or maybe it's software/firmware but we can't tell the difference so it doesn't matter).
So just when all this seemed to finally be completely clear I found this OWC adapter that claims to work with the M1 Mini or MacBook Air. It requires a driver even with MacOS, so I guess that shows the base M1 Mac's limitation is not intrinsically an M1 hardware issue.
eshop.macsales.com
OWC USB-C DUAL HDMI 4K DISPLAY ADAPTER WITH DISPLAYLINK
- Solution: easily solves the one external display limitation of Apple silicon M1 Macs
OWC USB-C Dual HDMI 4K Display Adapter with DisplayLink
Easily add two HDMI displays up to 4K to any Apple M1, M2 & M3 Mac or computer with a USB-C or Thunderbolt port. Includes a 1-year OWC warranty.
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It uses DisplayLink, not a DisplayPort or HDMI connection from a GPU. DisplayLink uses data over USB (1Gbps for 4K) instead of over DisplayPort (16 Gbps for 4K) which means it is greatly compressed. DisplayLink must use CPU and/or GPU resources to compress the data. DisplayLink might not be good enough for video or gaming. I guess you have to see it to know what it's good for.So just when all this seemed to finally be completely clear I found this OWC adapter that claims to work with the M1 Mini or MacBook Air.
OWC USB-C DUAL HDMI 4K DISPLAY ADAPTER WITH DISPLAYLINK
- Solution: easily solves the one external display limitation of Apple silicon M1 Macs
OWC USB-C Dual HDMI 4K Display Adapter with DisplayLink
Easily add two HDMI displays up to 4K to any Apple M1, M2 & M3 Mac or computer with a USB-C or Thunderbolt port. Includes a 1-year OWC warranty.
Yeah, I wasn't familiar with DisplayLink and didn't notice it required a MacOS driver to work until you were already responding. I design video equipment with HDMI/SDI, but I haven't had much reason to pay attention to these computer video interface options in years - until I ordered the new Mac Studio. Thanks again for this discussion.
Is it just me, or are there WAY too many ways to get a video signal from computer to monitor(s) these days? Is there a good explanation of all these options (HDMI, DP, TB4, USB-C, whatever+MST) along with their advantages and disadvantages? This reminds me of the old joke about standards being so wonderful that we need to have a lot of them.
TB and USB C video outputs are basically just DisplayPort in a different cable*. They both add the ability to carry power and TB adds extra bandwidth for monitor ports and things but the signal is just DP. MST is a feature of DP that allows for things like daisy chaining monitors together so they plug in with a single cable. For whatever reason Apple doesn't support MST despite it being a thing for years.
Its just best to use whatever connection will provide the greatest bandwidth on both ends, sometimes this is HDMI or DP depending on what versions your GPU or display supports so it's worthwhile to read the manual. Sometimes it makes no difference between the two.
*Technically there is an HDMI alt-mode for USB C but AFAIK nothing actually does and it's always DP converted to HDMI.
Its just best to use whatever connection will provide the greatest bandwidth on both ends, sometimes this is HDMI or DP depending on what versions your GPU or display supports so it's worthwhile to read the manual. Sometimes it makes no difference between the two.
*Technically there is an HDMI alt-mode for USB C but AFAIK nothing actually does and it's always DP converted to HDMI.
Myself and several coworkers just got company-issued 2020 MacBook Pros recently, and had to do a bunch of digging to find out how to get more than two displays (extended, not mirrored) going at once. I settled on a thunderbolt 3 dock with HDMI and Displayport connections, and a USB Displaylink HDMI adapter. Our office monitors are all 1080p60Hz panels, so using the USB adapter doesn't cause any loss in quality. (None that's noticeable on our cheapo ASUS monitors, anyways.)
This video -
- was the clearest explanation I found on how to get this kind of a setup going. Granted, we're dealing with Intel Macs, and not Apple Silicon, but it may still be useful.
This video -