Dell P3223QE dual monitors don't have same resolution on Mac Mini M2 Sonoma 14.5

[dmvmoe]

I've already concluded in order to have dual monitors on the mac mini one has to be plugged directly into the USB-C on the back the mini and the other I am using an 4K HDMI adapter (at least that what it says). I am trying to use anything higher than 2560x1440 on one of the monitors but it only goes to 3840x2160. I am reading so many articles and have tried every configuration I can on Sonoma 14.5 but can't for the life of me figure out what the issue is. I'm getting a cable delivered today which is a usb to hdmi and am going to plug that in to eliminate the adapter which if it works, great, then but then that leaves me with no more ports and I have a SSD T7 that I use and put my video editing files on. I've even tried adding custom scaled files i BetterDisplay but when I add them for that monitor, it says only Lo, no HiDPI scaling. It has to be that the adapter is converting it to something other than what it should and both HDMI cables are 4k/60 Hz which the Mini and the monitors are capable of handling. Can someone please tell me what I am doing wrong?

Also, let me add that I just put two usb-c cables into the mac mini and the dell and still, only one monitor gives me the extra resolutions and it's always the "extended" monitor.

[waydabber]

Hi @dmvmoe - I assume you have an M1 mini. Sadly the HDMI port (secondary display) can output a max resolution of 5K which is also a limit for the framebuffer (video memory) size. This means the max HiDPI resolution you can achieve is 2560x1440 (that results in a 5K image - as every logical pixel contains 2x2 framebuffer pixels). You get 3840x2160 as well because that is a LoDPI resolution and results in a 4K framebuffer that is inside the limit. A different cable will not solve this issue.

UPDATE: I see from the title that you have the M2 mini. What I just wrote still stands, the only difference with the M2 is that the secondary display can be connected via USB-C as well (but the framebuffer limits are still 6K for the primary, 5K for the secondary connection).

[dmvmoe]

Thank you for that and I guess this is a waste of a $500 monitor because these are not cheap. I'm not sure what to do now as 1440 is just not going to cut it. I'm going to assume as well that going to the Mini M2 Pro is probably going to have the same limitations. A big wasted screen for nothing sigh. Thank you again, I appreciate your input.

[waydabber]

No, the M2 Pro mini is better, it can support two displays up to 6K over USB-C/Thunderbolt (+ a third display over HDMI) so that should work better.