Issue with M4 Pro MBP and dual displays via TB5 dock

I'm looking at Technical Specifications and at the Support article for connecting monitors to a MacBook Pro – and I do not see anywhere where it says that you can connect two monitors running at a 144 Hz refresh rate to a M4 Pro MacBook Pro.

You say that you can connect both monitors (at 144 Hz?) when you connect them directly to the MacBook Pro, and you do a little song and dance.

So let's set that aside and look at how much data has to go over an external cable to the display(s). If we were talking about Thunderbolt 3 or 4, the usual rule of thumb is that a Mac can drive one 5K or 6K monitor at 60 Hz, or up to two 4K monitors running at 60 Hz.

• 5K @ 60 Hz = 14,745,600 pixels * 60 updates/second = 884,736,000 pixels/second
• 6K @ 60 Hz = 20,358,144 pixels * 60 updates/second = 1,221,488,640 pixels/second
• 4K @ 144 Hz = 8,294,400 pixels * 144 updates/second = 1,194,393,600 pixels/second
• Two of those 4K @ 144 Hz monitors = 2,388,787,200 pixels/second.

Driving two 4K monitors at 144 Hz requires sending out about 2x as many pixels per second as the number needed for a single 6K display! With Thunderbolt 3 or 4, this might be a problem …

If you're using a M4 Pro MacBook Pro which has Thunderbolt 5 ports, with a Thunderbolt 5 dock, the question then might become whether Apple has updated things to take advantage of Thunderbolt 5's increased bandwidth – or whether there might still be configuration limits in place that are based on the capabilities of Thunderbolt 3 and 4.

MacBook Pro (14-inch, M4 Pro or M4 Max, 2024) - Tech Specs - Apple Support

"M4 Pro

• Simultaneously supports full native resolution on the built-in display at 1 billion colors and:
• Up to two external displays with up to 6K resolution at 60Hz over Thunderbolt, or one external display with up to 6K resolution at 60Hz over Thunderbolt and one external display with up to 4K resolution at 144Hz over HDMI
• One external display supported at 8K resolution at 60Hz or one external display at 4K resolution at 240Hz over HDMI"

Use an external display with your MacBook Pro - Apple Support

"MacBook Pro with M4 or M4 Pro. You can connect up to two external displays in the following configurations:

• Connect one external display with up to 6K resolution at 60 Hz using a Thunderbolt port and one external display with up to 4K resolution at 144 Hz using the HDMI port.
• Connect up to two external displays with up to 6K resolution at 60 Hz using the Thunderbolt ports.

You can also connect a single display with up to 8K resolution at 60 Hz or up to 4K resolution at 240 Hz using the HDMI port."

CalDigit – Element 5 Hub

Caldigit's description claims that it is possible to attach "dual 4K 144 Hz" monitors to this hub, when using it with a M4 Pro MacBook. There is a footnote:

"Higher refresh-rates (above 60Hz) may require DSC (Display Stream Compression) support on the monitors and host GPU. The bit/color depth may vary in order to support higher refresh-rates."

What they're saying is that if either the Mac, or the monitors, do not support Display Stream Compression, you may not get the ability to run two 4K monitors at 144 Hz, after all.

You mentioned "AW2725Q" monitors. This appears to be a reference to. Dell – Alienware 27 4K QD-OLED Gaming Monitor - AW2725Q . It looks like DSC (Display Stream Compression?) is one of their features, though what you'd need to do to enable it, and whether the Mac supports it, are things I don't know offhand.