M2 MacBook Air + Dell S2722DC + Asus ProArt PA247CV

pedrinho_121 wrote:

Hello,

Sorry, it's still not clear to me... apparently both monitors support DisplayPort and can be connected between each other, right? MacBook Air M2 supports that, right?

Your monitors might support DIsplayPort MST daisy-chaining, but unless both the monitors and the computer support it, you're not going to get it.

The M2 MacBook Air only supports a single external monitor.

MacBook Air (M2, 2022) - Technical Specifications

MacBook Air (15-inch, M2, 2023) - Technical Specifications

Even Macs that support multiple external monitors typically do not support DisplayPort or USB-C (DisplayPort) daisy-chaining. Some support daisy-chaining two Thunderbolt monitors which have 4K resolution, or less. But Thunderbolt monitors are few and far between.

I was trying to connect:

1) MacBook Air M2 to Asus monitor via USB C to DisplayPort;

2) Asus monitor to Dell monitor via DisplayPort to USB C;

#1 would work if the Asus monitor was your only monitor, and assuming that you plugged the DisplayPort end of the cable into one of the monitor's DIsplayPort inputs. (The monitor might not take the signal if you plugged the cable into the DisplayPort MST output.).

#2 fails on a couple of counts, each of which is fatal. One is that the M2 MacBook Air supports only one monitor. Another is that I believe USB-C to DisplayPort adapters are meant to be used with the USB-C end plugged into a host USB-C (DP) port on a computer. Not to convert DP output from one monitor into USB-C (DP) input for another.

I believe that if you were using the monitors with a computer that supported multiple external monitors and that supported DIsplayPort daisy-chaining (e.g., a Windows PC with a suitable graphics card), you would

• Attach the first monitor to the computer using a USB-C to USB-C or USB-C to DisplayPort cable
• Attach one of the second monitor's DisplayPort input ports, to the first monitor's DIsplayPort MST output port, using a DisplayPort to DisplayPort cable

If you had a 14"/16" MBP that supported multiple external monitors, I can think of one way you might be able to attach both monitors to a single port on the MBP. This would involve the use of an OWC Thunderbolt Hub that splits one Thunderbolt chain into three Thunderbolt chains.

• Attach the OWC Thunderbolt hub to one of the 14"/16" MBP's USB-C (TB4) ports using a Thunderbolt cable
• Plug each monitor into one of the Thunderbolt hub's downstream ports using a USB-C to (whatever) cable.
• This would leave you with one open downstream USB-C (Thunderbolt) port, and a downstream USB-A port.
• To charge the laptop, you could plug a power adapter into the Thunderbolt hub. (I don't believe that it would pass charging power from the monitors through to the laptop.)

A Thunderbolt 3/4 connection can carry more data than a USB-C (DisplayPort) connection (first-generation one, anyway). So here, instead of having two monitors daisy-chained along a "thin pipe", you'd have a "fat pipe" that connected the MBP to the hub, which the hub then split up into two "thin pipes."

Or at least that's my understanding. I could be wrong.

But it's not working.

I bought the Dell monitor because I want to have 2 external displays with my MacBook Air M2 and it says in the product description and manual that it supports USB-C upstream with DisplayPort 1.2 (https://www.dell.com/en-us/shop/dell-27-usb-c-monitor-s2722dc/apd/210-bbqs/monitors-monitor-accessories). The Asus monitor supports also supports DisplayPort 1.2 by a Display Port downstream (https://www.asus.com/us/displays-desktops/monitors/proart/proart-display-pa247cv/).

In general, with computers, what you get is determined by the weakest link in the chain. If you place a USB 2.0 hub between your computer and your external SSD, which both have USB 3.1 Gen 2, you're not going to get the USB 3.1 Gen 2 ("up to 10 Gbps") speed. The hub is going to bottleneck you to 480 Mbps or less.

Your monitors may support DIsplayPort MST daisy-chaining, but your M2 MacBook Air does not support the use of multiple external monitors, and I don't know of any Mac that supports USB-C (DisplayPort) daisy-chaining.

So you're going to be able to connect at most ONE of your monitors to a first-class hardware video output. If you traded in the M2 MacBook Air for a 14" M2 Pro MacBook Pro, you'd need to plug the monitors into separate ports on the 14" MBP. (Unless you were using that OWC Thunderbolt Hub or another device like it.)

To attach both of those monitors to your M2 MacBook Air at the same time, you're going to need to use one of the third-party workaround solutions.

The Dell S2722DC is a 27" monitor with a resolution of 2560x1440 pixels. It has a USB-C (DisplayPort with Power Delivery Port) port, two HDMI ports, a couple of downstream USB ports, and a downstream audio line out port.

The Asus ProArt PA247CV is a 23.8" monitor with a resolution of 1920x1080 pixels. It has USB-C (DisplayPort with Power Delivery), a DisplayPort input, and a HDMI input. It has four downstream USB ports and a downstream audio port.

Your M2 MacBook Air only supports ONE first-class hardware video output. If you were connecting a single monitor directly to your M2 MacBook Air, you could use

• A USB-C to USB-C cable,
• A USB-C to DisplayPort adapter cable (Asus monitor only), or
• A USB-C to HDMI adapter cable

USB-C to USB-C would be preferred because it would hook up video, hook up downstream USB and audio output ports, and provide charging power to your laptop with a single cable connection.

Your MacBook Air will natively only support one external display. You can use a DisplayLink adaptor to connect two monitors. I've done this with a Plugable adaptor from Amazon, it works well

This is the one I'm using

https://www.amazon.ca/Plugable-DisplayPort-Monitor-Adapter-Compatible/dp/B08F2SZQYX?ref_=ast_sto_dp