How do I connect 2 x MSI Optix MAG321CURV monitors to my Macbook Pro M4 Pro 14"?

MSI – Optix Series LCD Monitor – Optix MAG321CURV / MAG322CQRV Manual

The Optix MAG321CURV is a 31.5" monitor with a resolution of 3840x2160 pixels and a refresh rate of 60 Hz. It has four video inputs:

• A USB-C (DisplayPort) input
• A DisplayPort input
• Two HDMI inputs

Many monitors that have USB-C inputs use USB-C not just for video, but to connect downstream hub ports and to provide substantial amounts of charging power. For this particular monitor, USB-C appears to support only video, and "up to 5V/3A (15W) power delivery" (which isn't much for charging a laptop).

You could connect this monitor to your M4 MacBook Pro by any of the following means:

• USB-C to USB-C, using a cable rated to carry video
• USB-C to DisplayPort, using an adapter or adapter cable
• USB-C to HDMI, using an adapter or adapter cable
• HDMI to HDMI

If you have two of them, and wanted to connect both without a dock, you could use USB-C to USB-C for one, and HDMI to HDMI for the other.

As far as Thunderbolt docks and dual-display adapters go, Other World Computing, SonnetTech, and CalDigit have many Thunderbolt docks (and a couple of Thunderbolt dual-display adapters) that might allow connecting both of these monitors to a single USB-C port on the M4 Pro MacBook Pro without using some second-class workaround.

BigRyanG wrote:

https://digital3d.com.au/products/satechi-usb-c-dual-multimedia-adapter-space-grey?variant=42150703169638&country=AU&currency=AUD&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&gad_source=1&gclid=Cj0KCQjw2N2_BhCAARIsAK4pEkV156-fU0YQ0brmNcywaDvUKF8qH2XEBq3l2Dl2o8eDpJh1HYCcXaIaAqJaEALw_wcB

That thing costs $199.99 – about as much as some Thunderbolt docks! It doesn't appear to be a Thunderbolt device. It appears to be one that takes up two USB-C ports to provide the equivalent of two inexpensive (~$20 each) USB-C to HDMI adapters.

If you wanted to use a dedicated dual-display adapter instead of a full-size dock, there are better options.

• Other World Computing – OWC Thunderbolt Dual DisplayPort Adapter – $50
• SonnetTech – Thunderbolt Dual 4K HDMI 2.1 Adapter – $100

Either of these would use just one of your USB-C (Thunderbolt) ports.

There are also some mini Thunderbolt docks with two video ports, a USB 3 port, and a USB 2 port:

• Other World Computing – OWC Thunderbolt mini Dock – $99
• CalDigit – Thunderbolt 3 Mini Dock

Plus lots of full-size Thunderbolt docks if those are what you are looking for.

Macs do not support driving two displays from a plain USB-C dock. If you look closely at the description of the J5 USB-C® Dual HDMI™ Docking Station, you'll see that driving two displays in extended desktop mode requires the installation of a driver. That is, the J5 is using a second-class "workaround" for one of its display outputs.

A MacBook Pro with a M4 Pro chip has the ability to drive two external displays, in a first-class, hardware-supported way, without workarounds – and the disadvantages that may accompany them.

To take advantage of first-class, hardware-supported video, it would be necessary to

• Connect the displays through different ports on the MacBook Pro, or
• Connect both displays through a genuine Thunderbolt dock or dual-display adapter.

"How do I connect 2 x MSI Optix MAG321CURV monitors to my Macbook Pro M4 Pro 14"?: Question is, now I have HDMI port, what is the most effective way to connect these dual monitors to the new M4 Pro?"

-------

Getting External Displays to Work:

Using a Hub, you can get this to work The J5 USB-C Dual HDMI Docking Station allows for more than two extra monitors. 

just connect the first with an HDMI-HDMI cable sold as at least PREMIUM. ULTRA is even higher spec and backwards compatible.

then connect the second with a high spec USB cable.

I can not recommend burning up two adjacent Thunderbolt ports just to drive two displays. Where do you plug in your other stuff if you do that?

As mentioned before, you may want to look at Thunderbolt docks and dual-display adapters from

• Other World Computing
• SonnetTech
• CalDigit

I do not have direct experience with any of these, but these three vendors have been in the business of selling Thunderbolt products to Mac users for a long time.

Connections vary, but may involve either

• One dedicated video port (DisplayPort or HDMI), plus the ability to plug a USB-C display or adapter into a Thunderbolt daisy-chaining port or downstream Thunderbolt hub port.
• Several downstream Thunderbolt ports and the ability to plug USB-C displays or adapters in up to two of them.

Usually the descriptions will come right out and say that you can attach up to two 4K displays, or one 5K/6K one.

There is a bandwidth limitation in HDMI version 2.0 that can force a tradeoff between 60 Hz and 8-bit-per-channel color versus 30 Hz and 10-bit-per-channel color. That can sometimes be a reason to prefer DisplayPort or USB-C over HDMI.

According to the manual, this monitor supports "16.7M" display colors. That is, it has 8-bit-per-channel color. So that's not going to be an issue.

"connected via a Satechi adaptor"

-------

Provide More of this Adapter:

What is this adapter you speak of? Where was this purchased? Can you provide the model and a photo of it? I am eager to know.