NEC PA322UHD will not work with Mac Studio Ultra at the native resolution of 3840x2160

I have the same monitor and the same studio Ultra.

I can get 3840x2160 4K 60Hz with no issues, I use a thunderbolt (USB C) to DP cable. Don't buy cheapest cable on Amazon, it needs to support DP1.2. The cable is about $40-$80 depending on length. I have no issues. same cable works with my old MBP

Interestingly when I use a high-speed HDMI cable I can only get 4K 30Hz but the DP port works. I think this monitor doesn't really support 4K 60Hz over the HDMI port, I had the same issue with my PC with Nvidia GTX 1080. Some owners claim changing the digital cable length option to 1 in the advanced menu can enable 4K 60Hz over HDMI but it didn't work for me.

If you read the manual some models come with a display card and switch board on the side of the monitor which you can pull out and toggle some switches there are 2 modes for HDMI 4K, 30Hz and 60Hz. maybe worth a try if you have the optional switch board. mine didn't have this option

hope this helps

What specific cables are you using and what do they say they can handle? Some can only go to 30Hz@4K

What resolutions are available when you open display preferences and and depress and hold the Option key and click on Scaled?

Have you tried the Display Menu app from the App Store to see what resolutions it offers?

Edit:

I just connected my M1 Macbook Air to my LG UHD monitor via USB-C>DP adopter with a DP-DP cable and got 3840x2160@60Hz with no problem.

Display works, computer works on a different port.

You have mostly eliminated all other issues and it is down to your cable, which is what lllaass was suggesting in the first response.

If you can get it working, DisplayPort (every version, encapsulated in ThunderBolt or USB or by itself) has higher bandwidth and runs cooler than HDMI.

There have also been quirks where certain displays would not work properly when their Internal on-screen-display settings were set to at HDMI 2.0 settings, but worked fine at HDMI 1.4 settings.

One difference is that HDMI 2.0 requires the display to do data decompression on the fly, which can be compute-intensive.

HDMI 4K @ 60 is very close to the limit of how fast digital signals can switch. HDMI up through 2.0 has only three data pathways in the cable, and is bandwidth-limited.

same problem as I have here:

12.3.1 update – no native resolutions on … - Apple Community

For some uses one is better than the other. For pros and cons see:

https://www.hp.com/us-en/shop/tech-takes/displayport-vs-hdmi

https://www.rtings.com/monitor/learn/hdmi-vs-displayport

https://www.pcmag.com/how-to/hdmi-vs-displayport-which-should-i-use-for-my-pc-monitor

12.3.1 that was released 4/1/22

IBC49 wrote:

What Mac OS are you using? I had just upgraded to Monterey 12.3

My experience with HDMI cables is the if they say only "High Speed" they will likely not work for 4K@60Hz.

I got two 8K@60 HDMI cable and they worked fine for my two 4K monitors @60Hz.

Yes these are 8K belkin cables rated for 8K or 4K 120 Hz.