Max vs Pro Processors and number of displays

[Stephen23]

Hello everyone,

I work as a multimedia artist for fine art and theater/dance. I've been waiting on the new Macs (with ports!) for ages, and my maxed out 2015 will finally be happy to have a rest as my daily driver.

I've seen the specs about the differences in the new Max vs Pro and what they can drive in terms of external displays at 4k and 6k, but has anyone seen any information about the maximum number of displays available in general? Most Mac laptops and iMacs have been limited to two external displays, which is a pain in the ass as three is a commonly requested number for presentation.

Since both the 14" and 16" have the same ports and processors, does anyone have a sense of whether they'll be able to drive four projectors or monitors (3 @ thunderbolt and 1 @ HDMI) running at 1080p? Or is there maybe a difference in what the Max can drive vs the Pro?

I know lots of people are going to say that if you're running multiples like that, you need to be using a Mac Pro or other dedicated system, and for larger projects we do that, but as someone who often does low budget productions with local dance companies as well, it would be very useful to have a laptop that could do three or four, and if I can spend a few hundred extra dollars for the max instead of pro, that capability is worth it.

Thanks!

 

[Krevnik]

M1 Pro drives 2 external displays. M1 Max drives 4.

 

[mystery hill]

M1 Pro - 2 external displays
M1 Max - 4 external displays

 

[joevt]

I think the specs imply 2 per Thunderbolt 4 port (otherwise Apple can't call them Thunderbolt 4) up to a max of 2 for M1 Pro and 4 for M1 Max. It's unknown if you can have all 4 displays on the left side of the M1 Max or if one of the four displays needs to be connected to HDMI port.

 

[rkulpajr]

I think the specs imply 2 per Thunderbolt 4 port (otherwise Apple can't call them Thunderbolt 4) up to a max of 2 for M1 Pro and 4 for M1 Max. It's unknown if you can have all 4 displays on the left side of the M1 Max or if one of the four displays needs to be connected to HDMI port.

I am pretty sure I saw in the keynote that one will need connected to the hdmi.

 

[darngooddesign]

I think the specs imply 2 per Thunderbolt 4 port (otherwise Apple can't call them Thunderbolt 4) up to a max of 2 for M1 Pro and 4 for M1 Max. It's unknown if you can have all 4 displays on the left side of the M1 Max or if one of the four displays needs to be connected to HDMI port.

I thought Apple said in the presentation that the Max could do one per TB port and one by HDMI for a total of 4.

 

[joevt]

I am pretty sure I saw in the keynote that one will need connected to the hdmi.

I thought Apple said in the presentation that the Max could do one per TB port and one by HDMI for a total of 4.

I don't think they said that was the only way to connect 4 displays but I didn't check (needs confirmation).

It might be true that only three can be connected to Thunderbolt. Since the ports are all Thunderbolt 4, then it must also be true that any one port can have two displays. If both of those are true, then the remaining question is: can you have three displays connected to a single side of the M1 Max MBP?

 

[darngooddesign]

I don't think they said that was the only way to connect 4 displays but I didn't check (needs confirmation).

It might be true that only three can be connected to Thunderbolt. Since the ports are all Thunderbolt 4, then it must also be true that any one port can have two displays. If both of those are true, then the remaining question is: can you have three displays connected to a single side of the M1 Max MBP?

Since Apple said that it’s one display per port, I doubt that it’s two per port.

 

[joevt]

Since Apple said that it’s one display per port, I doubt that it’s two per port.

If it's not two per port, then they can't call it Thunderbolt 4. Read Intel's requirements for the Thunderbolt 4 name.
The first M1 Macs could not do two per port so Apple called them Thunderbolt/USB4.

 

[Bigiain]

so in that sense inferior to my 3 year old <£1000 HP laptop that can drive 3 displays from a single connection to a thunderbolt port via a thunderbolt dock.

Guess I'm not moving to a mac in the near future. (i want to)

Unless someone can tell me an M1 Pro can drive 3 x QHD monitors from a single thunderbolt port (and charge)

 

[zakarhino]

so in that sense inferior to my 3 year old <£1000 HP laptop that can drive 3 displays from a single connection to a thunderbolt port via a thunderbolt dock.

Guess I'm not moving to a mac in the near future. (i want to)

Unless someone can tell me an M1 Pro can drive 3 x QHD monitors from a single thunderbolt port (and charge)

I'm pretty sure it can run multiple screens per port but it can only run ONE 6k panel per port due to the bandwidth necessary. A QHD screen is 2k so you should be able to run 3 from one port, right? I'm going to test when I get mind whether or not I can run my current setup of one 4k, one 2K monitor, and USB accessories from a single port.

 

[Bigiain]

I'm pretty sure it can run multiple screens per port but it can only run ONE 6k panel per port due to the bandwidth necessary. A QHD screen is 2k so you should be able to run 3 from one port, right? I'm going to test when I get mind whether or not I can run my current setup of one 4k, one 2K monitor, and USB accessories from a single port.

I'd be really interested to hear how you get on with that - I'm keen to move to a Mac for my personal laptop, but not at the expense of my 3 monitors with a single connection to the laptop.

I need to switch displays, mouse, keyboard, LAN etc. between my work and personal laptop with minimal disturbance - currently just 1 thunderbolt plug to move between the laptops.

Currently I'm running 1 monitor from the first display port on the dock and the other 2 monitors are daisy chained off the 2nd display port (using MST)

 

[joevt]

so in that sense inferior to my 3 year old <£1000 HP laptop that can drive 3 displays from a single connection to a thunderbolt port via a thunderbolt dock.

Guess I'm not moving to a mac in the near future. (i want to)

Unless someone can tell me an M1 Pro can drive 3 x QHD monitors from a single thunderbolt port (and charge)

No Thunderbolt dock can do more than two DisplayPort connections. I guess your Thunderbolt dock uses MST for additional displays. For example, the HP Thunderbolt Dock G2 can do 4 displays, 3 from its internal DisplayPort 1.4 MST hub and one from its downstream Thunderbolt port.
macOS has never supported MST for multiple displays so your issue is not new with M1 Macs.

One method to run more than two displays from a single Thunderbolt port in macOS is to use DisplayLink adapters. They use input from USB instead of DisplayPort.

I'm pretty sure it can run multiple screens per port but it can only run ONE 6k panel per port due to the bandwidth necessary. A QHD screen is 2k so you should be able to run 3 from one port, right?

XDR display can use DSC for 6K60. DSC reduces the required bandwidth from 38.9 Gbps to 15.4 Gbps so you can connect two of them to a single Thunderbolt 3/4 port.
A 2K displays is 8 Gbps but there aren't any Thunderbolt controllers that can put more than two DisplayPort connections on the same Thunderbolt cable (unless maybe you have an Intel Mac and connect a Blackmagic eGPU or a Sonnet Breakaway Puck RX 5500 XT or 5700 but I haven't seen anyone test that).

I'm going to test when I get mind whether or not I can run my current setup of one 4k, one 2K monitor, and USB accessories from a single port.

Shouldn't be a problem with just two displays. 16 Gbps + 8 Gbps = 24 Gbps. So write speed to USB accessories is at most 16 Gbps. Read speed should be up to ≈24 Gbps (depends on the USB controllers and USB hubs that are used in the chain).

I'd be really interested to hear how you get on with that - I'm keen to move to a Mac for my personal laptop, but not at the expense of my 3 monitors with a single connection to the laptop.

I need to switch displays, mouse, keyboard, LAN etc. between my work and personal laptop with minimal disturbance - currently just 1 thunderbolt plug to move between the laptops.

Currently I'm running 1 monitor from the first display port on the dock and the other 2 monitors are daisy chained off the 2nd display port (using MST)

macOS doesn't support MST for multiple displays since forever. macOS does support old 4K MST displays (they use two streams of 1920x2160) and it does support MST for converting DisplayPort link width and link rate. I don't think they changed that for the new M1 Macs?

Monterey adds VRR support (variable refresh rate) but is that only for M1 Macs? My Intel Mac doesn't have the VRR option with my GPU/display combo (W5700 and Acer XV273K). If Apple is adding M1 only features, then maybe MST for multiple displays could become a thing.

 

[nexxco]

I have a 4 monitor setup and about to buy the 14" M1 Max version. Trying to figure out how the docks/hubs situation works. Caldigit released an article saying their existing TB3 docks that have 2 video outputs (not displaylink) will work with M1 pro/max. Now I'm thinking all the other brands with TB3 to dual displayport/hdmi that used to say not compatible with M1 because those macbooks only support 1 external monitor, are they actually compatible with M1 pro/max now? Would be nice to just grab 2 of these TB3 to dual DP/hdmi to connect my 4 monitors instead of using up all 3 TB4 ports and hdmi.

 

[joevt]

Now I'm thinking all the other brands with TB3 to dual displayport/hdmi that used to say not compatible with M1 because those macbooks only support 1 external monitor, are they actually compatible with M1 pro/max now?

Basically all Thunderbolt hubs/docks/adapters can support two DisplayPort connections. They are all compatible with any M1 Mac. The problem with the first M1 Macs was that the second DisplayPort connection could only be used by a dual tile display (dual link SST display) such as the LG UltraFine 5K or Dell UP2715K.

Would be nice to just grab 2 of these TB3 to dual DP/hdmi to connect my 4 monitors instead of using up all 3 TB4 ports and hdmi.

We don't know if the Thunderbolt ports of the M1 Max support more than 3 displays. Some people say the 4th display needs to be connected to HDMI.

 

[Bigiain]

No Thunderbolt dock can do more than two DisplayPort connections. I guess your Thunderbolt dock uses MST for additional displays. For example, the HP Thunderbolt Dock G2 can do 4 displays, 3 from its internal DisplayPort 1.4 MST hub and one from its downstream Thunderbolt port.
macOS has never supported MST for multiple displays so your issue is not new with M1 Macs.

One method to run more than two displays from a single Thunderbolt port in macOS is to use DisplayLink adapters. They use input from USB instead of DisplayPort.


XDR display can use DSC for 6K60. DSC reduces the required bandwidth from 38.9 Gbps to 15.4 Gbps so you can connect two of them to a single Thunderbolt 3/4 port.
A 2K displays is 8 Gbps but there aren't any Thunderbolt controllers that can put more than two DisplayPort connections on the same Thunderbolt cable (unless maybe you have an Intel Mac and connect a Blackmagic eGPU or a Sonnet Breakaway Puck RX 5500 XT or 5700 but I haven't seen anyone test that).


Shouldn't be a problem with just two displays. 16 Gbps + 8 Gbps = 24 Gbps. So write speed to USB accessories is at most 16 Gbps. Read speed should be up to ≈24 Gbps (depends on the USB controllers and USB hubs that are used in the chain).


macOS doesn't support MST for multiple displays since forever. macOS does support old 4K MST displays (they use two streams of 1920x2160) and it does support MST for converting DisplayPort link width and link rate. I don't think they changed that for the new M1 Macs?

Monterey adds VRR support (variable refresh rate) but is that only for M1 Macs? My Intel Mac doesn't have the VRR option with my GPU/display combo (W5700 and Acer XV273K). If Apple is adding M1 only features, then maybe MST for multiple displays could become a thing.

Thanks for taking the time to write a comprehensive reply

You guessed right - its an HP Thunderbolt Dock G2

So an option avoiding MST could be having a QHD monitor on each of the dock's 2 DisplayPort outputs and put the 3rd monitor on the VGA output?

 

[joevt]

So an option avoiding MST could be having a QHD monitor on each of the dock's 2 DisplayPort outputs and put the 3rd monitor on the VGA output?

Everything is DisplayPort with USB-C or Thunderbolt. VGA or HDMI is output using DisplayPort adapters.

The MST Hub of the HP Thunderbolt Dock G2 has three outputs - USB-C DisplayPort Alt Mode port, DisplayPort 1, and DisplayPort 2. The VGA port shares the DisplayPort output of the MST Hub that is used for the USB-C DisplayPort Alt Mode port. When a display is connected to the VGA port, the DisplayPort is disconnected from the USB-C DisplayPort Alt Mode port but that USB-C port can still be used for USB devices. For macOS, if you connect more than one display to the MST Hub ports then they will be mirrored.

For macOS, one display can be connected to one of those 4 ports. A second display can be connected to the downstream Thunderbolt port. Additional displays can be connected using DisplayLink adapters that are connected to the USB ports of the dock.

For Windows, you can connect three 4K 60Hz display just to the MST Hub ports alone (but you need to make sure the firmware of the dock is updated to support DSC, and your GPU needs to support DSC). If DSC is not supported, then the displays need to be lower res or lower refresh rate.