I did a lot of testing with these two ThinkPads and the additional equipment. I would like to keep the AMD device and return the Intel. But the AMD has some driver or firmware issues.
What I would like to do:
I would like to use the AMD Thinkpad with two, three or four external displays with 4k or 7680x2160 resolution each.
The minimum configuration should be 1x 7680x2160 + 1x 4k in combination with the TB4 dock only.
My desired configuration would be a 1x 7680x2160 + 2x 4k in combination with the TB4 dock and the USB-C to DisplayPort adapter cable.
The 7680x2160 monitor also supports picture by picture mode, which means it can be used like two individual 4k displays with two monitor cables. Which means, a 4x 4k display setup would be also a possible solution.
I am pretty sure that the RDNA3 / 780m is powerful enough to drive this amount of pixels in a business setup.
Here is the problem:
With the Intel device, the following display setups just work fine in combination with the TB4 Dock:
Its not possible to use 3x 4k. And its not possible to use 1x 7680x2160.
In general, its not possible to configure more than 4k resolution for monitors, no matter if the monitor is connected over to the USB4 port over the TB4 Dock or if its connected to the HDMI 2.1 port. Even the maximum resolution for the HDMI 2.1 port is also capped at 4k.
But: When I connect the Neo G9 57" with the USB-C to DisplayPort adapter cable to the USB3.2 Gen 2 or the USB4 port of the AMD device, I can configure 7680x2160 with up to 120Hz with 10bit!
Thats the same like 8k @ 60Hz with 10bit. Or the same like two 7680x2160@60Hz 10bit displays. So, the 780m is powerfull enough for a good multi display setup.
Are there any chances to see better support for the Neo G9 57" / Dual UHD displays and TB4 dock support in the near future?
The full sized Radeon 7000 RDNA3 cards support this resolution very well with up to 240Hz. Would be nice to see this support in the mobile section as well.
PS: I tried all of this with the default windows drivers and of course with the latest AMD chipset/cpu and Adrenalin driver packages.