Dell Alienware AW3225QF with Macbook Pro M1 Max - 4K/120Hz/95Hz + HDR

[alfogator]

I'm posting here my findings to help anyone that is using a similar setup and might find them useful.

I'm using the DisplayPort connection on the monitor for my PC so I wanted to find a way to use the HDMI port. The builtin port in the MBP M1 is Hdmi 2.0 so limited to 60 Hz.

I used the information in this thread:

DP/USB-C/Thunderbolt 3/4 to HDMI 2.1 4k@120hz RGB4:4:4 10b HDR with Apple Silicon M1/M2/M3 now possible !

WARNING 31.10.23: macOS Sonoma 14.1 and newer breaks HDR with HiDPI 4k@120hz 4:4:4 and beyond. We are looking for a solution. NOTE: To ensure proper credit for this solution, kindly reference this thread when sharing. Thanks! Apple limited HDMI-Transportstream over USB-C/TB/DP to maxed...

forums.macrumors.com

and flashed a Cable matters usb-c to HDMI adapter. This works perfectly and out of the box I can have 4K@120Hz with 10bit RGB.

HDR is not available with 4K/120Hz. I read in a support notice from Apple that due to "issues" they are limiting HDR to lower resolution/refresh rates signals only. So I did some experimenting and by creating a custom 4K@95Hz HDR is available up to a scaled resolution of 2720x1530.

I'm using BetterDisplay to load the custom EDID at boot and I usually keep 2720x1530 and switch between 120Hz for SDR and 95Hz for HDR content.

Input source switching also works perfectly with BetterDisplay so I mapped a shortcut to swap between DP and HDMI.

 

[bozo_z_clown]

HDR is not available with 4K/120Hz. I read in a support notice from Apple that due to "issues" they are limiting HDR to lower resolution/refresh rates signals only. So I did some experimenting and by creating a custom 4K@95Hz HDR is available up to a scaled resolution of 2720x1530.

Thanks for the tip … I was wondering why I couldn't get HDR on my spiffy new monitor but I'd set it to 120Hz

 

[biopig]

I got the same setup: AW3225QF and MBP M1 Max. But I also added a DisplayPort KVM switch so that I can hook up the monitor thru DP cable and it gives me full VVR and HDR capabilities, also spare the HDMI port for Apple TV and Nintendo Switch

 

[alfogator]

I got the same setup: AW3225QF and MBP M1 Max. But I also added a DisplayPort KVM switch so that I can hook up the monitor thru DP cable and it gives me full VVR and HDR capabilities, also spare the HDMI port for Apple TV and Nintendo Switch

Which kvm switch did you use?

 

[biopig]

Which kvm switch did you use?

it's Cable Matters DP KVM, I use it to switch between MBP and Alienware desktop pc. Fully 4K @ 120Hz (or VRR up to 120Hz) and HDR support. (Also I connect a second 4K monitor directly to MBP and it gets 95Hz, 3 years old M1 Max still rocks!) Works perfectly with eARC speakers thru the eARC port on monitor, in this case I got SONOS Beam 2 with Dolby Atmos audio.

Cable Matters USB 3.0 KVM Switch DisplayPort 1.4 for 2 Computers with 8K@60Hz / 4K@240Hz Display Port Video & 3X 5Gbps USB Ports, FreeSync, G-SYNC and HDR Support - RF Remote Control Switch

More Power, Less Cables The Cable Matters USB KVM Switch DisplayPort is the ultimate space-saving accessory for the mobile worker. Share an 8K or 4K 240Hz monitor, a keyboard, a mouse, and a flash drive with up to 2 computers. Eliminate the need for separate pairs of monitors, keyboards, mice, pr...

a.co

 

[unphased]

I am putting my AW3225QF through its paces paired with my macbook as it's a beautiful screen for coding. It's not ideal in a few areas but most of it is down to the age of my M1 Max MBP.

My understanding of how this stuff works is:

HiDPI modes render internally on the GPU at double resolution. For example, I can see that BetterDisplay lets me choose 3840x2160 (4K) in plain (direct native resolution of monitor) or HiDPI mode, the latter of which would cause the GPU to internally render 8K (7680x4320). Accordingly the mode I was trying to use in HiDPI (since it has good UI sizes, or so I thought), 3008x1692, would indeed render internally at 6016x3384. This is, well, still an insanely huge resolution.

I found that I could not enable HDR reliably at 3008x1692HiDPI. I don't doubt that this has to do with difficulties dealing with such a large buffer at higher bitdepth required for HDR rendering.

So I can get 120hz 4K by not using HiDPI or (as another commenter has mentioned already) by not using too high of a HiDPI resolution... curiously 2720x1530 is NOT in my list of possible resolutions to use. I am currently evaluating 2560x1440HiDPI for daily use, as it seems to also support both 120hz and HDR. I think especially on a 240hz panel I should not want to settle for any less than 120hz which is standard on the macbook's own display also. I think 2560 is an acceptable resolution, it is 5K and not too much more taxing than the native 4K, while providing a nice clean upscaled look on text and UI which I have come to like (subpixel rendering especially of text is a weak point of modern macOS). Still I can definitely feel a good deal of skipped frames in things like Neovide so time will tell if I will find it acceptable.

I also have a base model M4 Mac Mini that I am looking forward to test with this monitor. It should be able to drive 4k 240hz, I do not know how HDR will change things.