2 Monitors on an Intel Mac Mini?

[Hrothgar]

I've got a Mac Mini (2018); 3.2 Ghz 6-Cor Intel Core i7.
I'm using a Dell monitor connected with displayport. I tried adding a second Dell monitor, with displayport daisychained, and I'm getting the screens mirrored. I don't see an option to extend them so I have the benefit of twice the screen space. My googling suggests this cannot be done.
I find it hard to believe that people working with Macs don't use two monitors.

Can someone help me out? Thanks.

 

[Chicago Keri]

There should be an option for "Mirror Displays" under System Preferences > Displays... Either click on the gear icon in the Dock or the Apple logo in the upper left corner of the screen. If the daisy chain doesn't work, you'd probably have to use 2 separate ports.

 

[theluggage]

I'm using a Dell monitor connected with displayport. I tried adding a second Dell monitor, with displayport daisychained, and I'm getting the screens mirrored.

Last I looked, Macs don't support DisplayPort daisy-chaining at all. The Intel Mini should support 2-3 displays but they both have to be connected directly to the USB-C or HDMI ports.

 

[Hrothgar]

Figured it out. Needed two cables. Funny, my old mini couldn't have two different output formats.

 

[joevt]

DisplayPort daisy-chaining is where a display acts as a DisplayPort MST Hub. The display has a DisplayPort input (the MST hub's inputs) and two outputs (the MST hub's outputs). One output is internal and is used by the display. The other output is external and can be used to connect another display. You can daisy chain multiple displays this way. The last display can be a normal display that does not support daisy chaining.

macOS does not support MST for multiple displays. They will be mirrored. Use Boot Camp or Linux to see multiple displays.
Read more about MST hubs at https://insights.club-3d.com/thread/csv-1550-display-connection-might-be-limited/

Maybe lack of support for MST is one reason why Apple will not report what version of DisplayPort a Mac supports (i.e. can't really say DisplayPort 1.2 is supported if you don't support MST).

Anyway, in the case of the Mac mini 2018, if you want to connect two DisplayPort displays to the same port, then use a Thunderbolt dock or a Thunderbolt to Dual DisplayPort adapter. Thunderbolt will have double the bandwidth of DisplayPort MST. A single Thunderbolt connection can do two 4K 60Hz 10bpc RGB displays, while DisplayPort 1.2 MST can only do two 4K 30Hz displays (or 1440p60 displays).

 

[Hrothgar]

Right now I've got DP into one monitor and HDMI into the other. Would I do better with a Thunderbolt to Dual DP adapter? Or, I guess, at TB to dual TB adapter?
What I've got now seems fine for me. I'm not gaming, just doing Word, Adobe, Outlook and similar.

Thanks for the advice.

 

[joevt]

Right now I've got DP into one monitor and HDMI into the other. Would I do better with a Thunderbolt to Dual DP adapter? Or, I guess, at TB to dual TB adapter?
What I've got now seems fine for me. I'm not gaming, just doing Word, Adobe, Outlook and similar.

DisplayPort 1.2 has slightly more bandwidth than HDMI so if you're doing 4K 60Hz and want HDR or 10bpc, then DisplayPort 1.2 is the way to go. That can only come from the Thunderbolt port. So either use two Thunderbolt ports or use a Thunderbolt to Dual DisplayPort adapter or a Thunderbolt Dock. I don't think Word, Adobe, Outlook and similar benefit much from 10bpc.

 

[theunk]

Right now I've got DP into one monitor and HDMI into the other. Would I do better with a Thunderbolt to Dual DP adapter? Or, I guess, at TB to dual TB adapter?
What I've got now seems fine for me. I'm not gaming, just doing Word, Adobe, Outlook and similar.

Thanks for the advice.

I don’t think macOS supports extended mode period. I have a TB to dual HDMI and can only get mirrored display. You probably have as good as your going to get for awhile.

 

[joevt]

I don’t think macOS supports extended mode period. I have a TB to dual HDMI and can only get mirrored display. You probably have as good as your going to get for awhile.

Do you have an Intel Mac? Are you sure the TB to dual HDMI adapter is not a USB-C to dual HDMI adapter? (provide a link to the adapter and describe how it is connected)

 

[sublunar]

I assume that you'd have to use the HDMI port for connection to one monitor and one of the Thunderbolt ports (with an adapter) to connect the other one.

As the OP mentions Dell monitors with DP connections they would need 2 adapters (USB-C display to DP, HDMI to DP)

As others have mentioned you can't daisy chain from one to the other. I use a single Thunderbolt cable to a dock and that dock has USB-C and DP ports to 2 separate monitors if you need to save a port.

 

[joevt]

I assume that you'd have to use the HDMI port for connection to one monitor and one of the Thunderbolt ports (with an adapter) to connect the other one.

Intel Mac mini 2018 supports three displays total - one from HDMI and two displays from Thunderbolt (two displays connected to a single Thunderbolt device, or connected to two different Thunderbolt ports)

M1 Mac mini supports two displays total - one from HDMI and one from Thunderbolt. The one connected to Thunderbolt may be a dual tile display that uses two DisplayPort connections over Thunderbolt (such as the Dell UP2715K or LG UltraFine 5K). The second DisplayPort connection of Thunderbolt cannot be used by a single tile display.

Therefore, I asked @theunk if he had an Intel Mac and a Thunderbolt adapter. If the answer is no to either, then no wonder his adapter didn't work. It is possible that the answer is yes to both, therefore I asked what the exact model of the adapter is and what else is connected so we may discover why it doesn't work or at least what adapter to avoid.

 

[sublunar]

Intel Mac mini 2018 supports three displays total - one from HDMI and two displays from Thunderbolt (two displays connected to a single Thunderbolt device, or connected to two different Thunderbolt ports)

M1 Mac mini supports two displays total - one from HDMI and one from Thunderbolt. The one connected to Thunderbolt may be a dual tile display that uses two DisplayPort connections over Thunderbolt (such as the Dell UP2715K or LG UltraFine 5K). The second DisplayPort connection of Thunderbolt cannot be used by a single tile display.

Therefore, I asked @theunk if he had an Intel Mac and a Thunderbolt adapter. If the answer is no to either, then no wonder his adapter didn't work. It is possible that the answer is yes to both, therefore I asked what the exact model of the adapter is and what else is connected so we may discover why it doesn't work or at least what adapter to avoid.

My reply was based purely on likely physical connectivity options being used by @Hrothgar - I am aware of intel minis supporting 3 displays on the 2018 model but he was only using 2 displays anyway.

TB to Dual HDMI as per @theunk might be an unworkable solution because of the display streams, I don't use it because I have a TB dock which has TB3 passthrough and DP and it's from there that I get 2 displays running from my Caldigit TS3+ off one Thunderbolt 3 connection.

 

[joevt]

TB to Dual HDMI as per @theunk might be an unworkable solution because of the display streams, I don't use it because I have a TB dock which has TB3 passthrough and DP and it's from there that I get 2 displays running from my Caldigit TS3+ off one Thunderbolt 3 connection.

Some old Thunderbolt 3 devices use the TI82 chip. Apple does not allow those to work. For macOS, they need the TI83 chip. You can override that with https://github.com/rgov/Thunderbolt3Unblocker That is one of the possible reasons @theunk's adapter doesn't work but it would be nice to know what the adapter was so we could know for sure.

 

[InuNacho]

Word of warning about using the HDMI port on the Mini, it is VERY flaky and gave me tons of issues.
I eventually gave up entirely on the HDMI port and went with one of these J5 Create USB C to DisplayPort cables on eBay for less than $10. Rock solid. I have tested it and it works well with hubs.

EDIT: I realize I should have given a bit more info. This is connected to my older Dell U2410 so its only 1920x1200 resolution. I did also test this on my Dell U3011 @ 2560x1600 and again, works flawlessly.

 

[sublunar]

Word of warning about using the HDMI port on the Mini, it is VERY flaky and gave me tons of issues.
I eventually gave up entirely on the HDMI port and went with one of these J5 Create USB C to DisplayPort cables on eBay for less than $10. Rock solid. I have tested it and it works well with hubs.

EDIT: I realize I should have given a bit more info. This is connected to my older Dell U2410 so its only 1920x1200 resolution. I did also test this on my Dell U3011 @ 2560x1600 and again, works flawlessly.

The HDMI port might be the source of a lot of issues with sleep/wake causing multiple generations of mini from 2012-2018 (even M1?) to not wake up on time. I guess it would be more of an issue with the M1 Mini with it having just two TB3 ports. If you have to use one of them to attach a display (without going through a dock) it's a bit of a waste of a precious port, especially if you were hoping to use two displays.

For me, I am waiting on what the upper SKU of the mini will turn out to be - I'm sure many folks will just be happy with an M1X - interpreting that as 8 performance cores, 2 efficiency cores, 4 proper thunderbolt ports, and the new case configuration to possibly eliminate the wifi/bluetooth issues.

 

[InuNacho]

The HDMI port might be the source of a lot of issues with sleep/wake causing multiple generations of mini from 2012-2018 (even M1?) to not wake up on time. I guess it would be more of an issue with the M1 Mini with it having just two TB3 ports. If you have to use one of them to attach a display (without going through a dock) it's a bit of a waste of a precious port, especially if you were hoping to use two displays.

For me, I am waiting on what the upper SKU of the mini will turn out to be - I'm sure many folks will just be happy with an M1X - interpreting that as 8 performance cores, 2 efficiency cores, 4 proper thunderbolt ports, and the new case configuration to possibly eliminate the wifi/bluetooth issues.

That is true, it is a complete waste of a good TB port but I imagine displaying an image on the screen shouldn't eat all bandwidth of TB3. There are alot of cheap Dell and HP TB3 docks out there ewaste facilities sell for less than $50.
My bud works in one such place and gave me this HP Elite HSTNNC-CX01 for free. I haven't tested it yet but it has 2x native DisplayPorts.

 

[twisted-pixel]

Intel Mac mini 2018 supports three displays total - one from HDMI and two displays from Thunderbolt (two displays connected to a single Thunderbolt device, or connected to two different Thunderbolt ports)

Is there any reason for this?

right now I have a MacBook Pro (2018) and two external monitors. I was going to upgrade the MacBook, but instead opted for a 2021 Intel Mac mini and will connect three monitors (just standard 1080p monitors). I see that two can be connected to the thunderbolt ports, but one has to be on the HDMI port. Seems odd, that I can't simply connect three monitors via the thunderbolt ports

 

[joevt]

Is there any reason for this?

Mac mini 2018 uses Intel GPU. Intel GPUs have 3 outputs. Add more GPUs to add more displays. AMD GPUs can do 6 (or 5). Nvidia usually can do 4.

right now I have a MacBook Pro (2018) and two external monitors. I was going to upgrade the MacBook, but instead opted for a 2021 Intel Mac mini and will connect three monitors (just standard 1080p monitors). I see that two can be connected to the thunderbolt ports, but one has to be on the HDMI port. Seems odd, that I can't simply connect three monitors via the thunderbolt ports

Mac mini 2018 is the latest Intel Mac mini (Macmini8,1).
Since Intel GPU has only 3 outputs, and one is used for HDMI, only two remain for Thunderbolt.
I suppose Apple could have added a switch to allow the output connected to the HDMI port to be diverted to a Thunderbolt port but they did not.
They do have a switch to allow the other two outputs to be used by any of the two Thunderbolt controllers - either both to one controller or one to each controller.

M1 Mac mini (Macmini9,1) only supports two displays. One from HDMI and one from Thunderbolt.

 

[Solenoid289]

I use Blackmagic eGPU Radeon Pro 580 on my Mac mini 2018.
It supports at least 3 monitors with Thunderbolt to dual DsiaplayPort adaptor and HDMI.
Possible more monitors with daisy chain or using different eGPUs like Vega 64, 6700XT etc.

 

[joevt]

I use Blackmagic eGPU Radeon Pro 580 on my Mac mini 2018.
It supports at least 3 monitors with Thunderbolt to dual DsiaplayPort adaptor and HDMI.
Possible more monitors with daisy chain or using different eGPUs like Vega 64, 6700XT etc.

Blackmagic eGPU Radeon Pro 580 can only support 3 displays in macOS. It's strange because normally the Radeon Pro 580 can do 4 or 5 or 6. I suppose it could do 6 in Windows using two MST hubs (because macOS doesn't support MST for multiple displays) but they would be limited to dual HBR2 x4 bandwidth since Thunderbolt can't do dual HBR3 x4 and Radeon Pro 580 doesn't support DSC. Windows might have issues with eGPUs like the BlackMagic or Sonnet that have a second Thunderbolt port? Check egpu.io for more info.
But you can connect 3 to the Mac mini 2018 still, plus 3 from the Blackmagic makes 6.

 

[Amethyst1]

Blackmagic eGPU Radeon Pro 580 can only support 3 displays in macOS.

Even when eg daisy-chaining two Thunderbolt monitors off a single port?

 

[joevt]

Even when eg daisy-chaining two Thunderbolt monitors off a single port?

Blackmagic 580 has one Thunderbolt port and one HDMI port = 3 displays max. Blackmagic eGPU Pro has an additional DisplayPort for a fourth display but it is discontinued.

Thunderbolt monitors get DisplayPort from the upstream GPUs that are connected to Thunderbolt controller DisplayPort inputs (two per controller).
Now, the Mac mini 2018 has a Thunderbolt controller with two DisplayPort inputs, and the Blackmagic eGPU has a Thunderbolt controller with two DisplayPort Inputs, so theoretically, you could connect four displays to the Thunderbolt port of the Blackmagic eGPU. Two would be controlled by the AMD GPU and two would be controlled by the Mac mini 2018's Intel GPU. I don't think anyone has tried this - the OS might not allow it. The displays would need to be connected so that they only use HBR link width (1440p) because Thunderbolt 3 couldn't do more than 4 of those. Two displays can be connected to the last Thunderbolt device in the chain, therefore you need a Thunderbolt device for each of the displays before that (a Thunderbolt Display is a Thunderbolt device with built-in display so they'll do the job), or maybe a Thunderbolt 4 hub could work - they have three downstream Thunderbolt ports, so two Thunderbolt ports can be used for two displays and one Thunderbolt port can be used to connect the downstream Thunderbolt device for the other two displays.

 

[roman.stapunov]

I have Mac mini 2018. Tb3 to dual DP adapters works fine. Tb3 to dell up2720q and second ASUS ms27aq to dell tb3 output to DP works fine for me. You need to use correct adapter then it will work fine. I don’t use HDMI connection as it works with bugs since El Capitan

 

[Amethyst1]

I have Mac mini 2018. Tb3 to dual DP adapters works fine. Tb3 to dell up2720q and second ASUS ms27aq to dell tb3 output to DP works fine for me.

Does that mean you get two independent monitors, i.e. they are not mirrored?

 

[theunk]

Do you have an Intel Mac? Are you sure the TB to dual HDMI adapter is not a USB-C to dual HDMI adapter? (provide a link to the adapter and describe how it is connected)

Sorry for the delay. I have the 2018 Intel mini. The adapter I tried was a promotional offer https://www.amazon.ca/Adapter-Conve...LDAY+dual&qid=1628277648&s=electronics&sr=1-2

The manufacturer states that it doesn't support extended display mode in macOS.
When I got it, HDMI was being a real PITA, but is now working just fine. When HDMI was not working, this splitter adapter gave me two greenish mirrored displays. Now that HDMI is working, connecting both displays to this splitter only provides output to one display, the other is reporting "out of range".
What I have is working, I am not overly concerned, but the adapter market place is certainly challenging.