4K60Hz M1 Max Older Monitor

[Vlade]

Just got my new M1 Max and it's great, except 4K will only go up to 30Hz, unlike my 2013 and 2018 Intel MBPs which I've been using at full res/refresh rate for seven years. I've tried two USB-C/Thunderbolt to MiniDisplayPort dongles, and a new USB-C-Displayport cable. All rated for DP1.2+ and all work just fine on my Intel MBP, but none will hit 60HZ on the new M1 past 1900x1200 resolution. I have a Dell UP3214Q, it has DisplayPort 1.2 so it can handle it, HDMI is old and limited to 30Hz at 4k.

Any ideas on how to get this monitor running at non-nauseating resolution/refresh rates? I've tried a few apps to force resolutions and three pieces of hardware, option clicked the Scaled button in the displays system preferences, and everything else I can think of. I don't have a good use for this 32" Dell 4K display and am trying to avoid buying a more modern monitor after dropping 3500 on this laptop...

 

[pshufd]

I'll give it a shot tonight.

 

[metapunk2077fail]

Many cables are mislabeled not what they are rated for. Cable Matters are the best.

 

[Vlade]

Thanks Pshufd!

Right on cables but all three that I've tried are reputable and work correctly on the Intel MacBook Pro

 

[bhodinut]

I have an Anker USB-C to HDMI that does 60hz on my M1 Pro. I have one monitor that won't go above 30hz on HDMI. However, on a newer monitor I can get 60hz on either HDMI or DISPLAYPORT with my M1 Pro MacBook

 

[joevt]

Just got my new M1 Max and it's great, except 4K will only go up to 30Hz, unlike my 2013 and 2018 Intel MBPs which I've been using at full res/refresh rate for seven years. I've tried two USB-C/Thunderbolt to MiniDisplayPort dongles, and a new USB-C-Displayport cable. All rated for DP1.2+ and all work just fine on my Intel MBP, but none will hit 60HZ on the new M1 past 1900x1200 resolution. I have a Dell UP3214Q, it has DisplayPort 1.2 so it can handle it, HDMI is old and limited to 30Hz at 4k.

Any ideas on how to get this monitor running at non-nauseating resolution/refresh rates? I've tried a few apps to force resolutions and three pieces of hardware, option clicked the Scaled button in the displays system preferences, and everything else I can think of. I don't have a good use for this 32" Dell 4K display and am trying to avoid buying a more modern monitor after dropping 3500 on this laptop...

Is the DisplayPort 1.2 option enabled in the Dell's menu?

The Dell UP3214Q is an old 4K MST display. That means it uses DisplayPort 1.2 MST to do 4K 60Hz by outputting two streams, one for the left half and another for the right half of the display (each 1920x2160 pixels).
https://forums.macrumors.com/thread...underbolt-1-awesomeness.2309427/post-30408547

While macOS doesn't support MST for multiple displays, it does support MST for these old 4K MST displays. Maybe M1 Macs don't have the 4K MST display support anymore? Did you try an Intel Mac?

 

[Vlade]

Is the DisplayPort 1.2 option enabled in the Dell's menu?

The Dell UP3214Q is an old 4K MST display. That means it uses DisplayPort 1.2 MST to do 4K 60Hz by outputting two streams, one for the left half and another for the right half of the display (each 1920x2160 pixels).
https://forums.macrumors.com/thread...underbolt-1-awesomeness.2309427/post-30408547

While macOS doesn't support MST for multiple displays, it does support MST for these old 4K MST displays. Maybe M1 Macs don't have the 4K MST display support anymore? Did you try an Intel Mac?

Yeah, It is enabled, tried factory resetting and enabling, restarting everything.

Thanks for the MST info, I wasn't aware of that MST/SST difference but I'm willing to bet that is the problem. Seems unlikely they'll add support too after a year of M1 Macs being out there. Or if they do it will be one day past my return window on a new monitor. Bummer since it does work on both Intel Macs...

Edit - Idea, I'll go try at least HDMI on my 2019 LG 4k TV, I don't know that I have any other DisplayPort monitors to try though

 

[Vlade]

Update - Tried HDMI directly to my TV and it works at full res/refresh.

On another note, I paid $2400 in 2014 for my monitor and haven't looked at prices since then. It appears now that 32" 4k displays start at $300, so it may not be the end of the world after all!

 

[Amethyst1]

HDMI is old and limited to 30Hz at 4k.

The HDMI port might be good for slightly higher refresh rates. If doing this is now possible on M1, creating a custom "4K" timing in SwitchResX with a 38.5 Hz refresh rate using CVT-RB timings might be worth testing. My slightly newer (January 2015) Dell P2415Q does "4K" at 60 Hz via DisplayPort 1.2 SST and "4K" at 38.5 Hz (using CVT-RB timings) via its HDMI 1.4 port. Using tighter CVT-RBv2 timings, I can get 39.3 Hz. I find the difference between 30 and 38.5/39.3 Hz eliminates the urge to throw the monitor out the window, provided it's not my primary monitor.

 

[Vlade]

The HDMI port might be good for slightly higher refresh rates. If doing this is now possible on M1, creating a custom "4K" timing in SwitchResX with a 38.5 Hz refresh rate using CVT-RB timings might be worth testing. My slightly newer (January 2015) Dell P2415Q does "4K" at 60 Hz via DisplayPort 1.2 SST and "4K" at 38.5 Hz (using CVT-RB timings) via its HDMI 1.4 port. Using tighter CVT-RBv2 timings, I can get 39.3 Hz. I find the difference between 30 and 38.5/39.3 Hz eliminates the urge to throw the monitor out the window, provided it's not my primary monitor.

Great idea, but after not having any luck with custom settings I just found this on their website here https://www.madrau.com/srx_howtouseit/srx_howtouseit/srx_timings.html - "This feature is not available yet on Apple Silicon Macs"

I'm hoping I can find a good use for it as a third monitor if I have go with a new one, I already have a few ideas of static info that I could leave up there as a reference at 30Hz

 

[Amethyst1]

Great idea, but after not having any luck with custom settings I just found this on their website here https://www.madrau.com/srx_howtouseit/srx_howtouseit/srx_timings.html - "This feature is not available yet on Apple Silicon Macs"

Pity

 

[pshufd]

I finally got around to setting up the M1 PRO MacBook Pro 16 with two external 4k monitors and both are running at 60 hz. The first display is a Dell U2720Q and the connection is via a Belkin Thunderbolt 3 USB-C cable at 18 inches. The second display is an older Dell U2718Q and is connected by a Cable Matters USB-C to DisplayPort 1.4 cable supporting 8K at 60 hz at 6 ft long.

I was rather picky about the cables because I have had problems in the past and because of all of the cautions in these forums on choosing the right cable and a good quality cable.

Cable Matters 32.4Gbps USB C to DisplayPort 1.4 Cable 6 ft, Support 8K 60Hz / 4K 144Hz (USB-C to DisplayPort, USB C to DP Cable) in Black - Thunderbolt 4 / USB4 Compatible with iPhone 15, MacBook, XPS

Experience Vivid 4K Video over DisplayPort The Cable Matters USB Type-C to DisplayPort Cable supports the newest release computers and smartphones with USB-C or Thunderbolt 3 up to 4K 60Hz UHD display monitors with DisplayPort. Experience the vibrant video and authentic audio supported by monitor...

www.amazon.com

Belkin Thunderbolt 3 Cable (USB-C to USB-C) - USB C Cable For MacBook Air, Galaxy, Apple TV & More, Fast Charging Up To 100W, Made For USB-C, Thunderbolt 3 devices & 5K/Ultra HD - 1.6ft/0.5m - Black

Belkin Thunderbolt 3 Cable (USB-C to USB-C) - USB C Cable For MacBook Air, Galaxy, Apple TV & More, Fast Charging Up To 100W, Made For USB-C, Thunderbolt 3 devices & 5K/Ultra HD - 1.6ft/0.5m - Black

www.amazon.com

 

[Amethyst1]

I'm hoping I can find a good use for it as a third monitor if I have go with a new one, I already have a few ideas of static info that I could leave up there as a reference at 30Hz

Sorry that I haven't replied earlier, but there might (the same-generation Dell UP2414Q is limited to 30 Hz even in PBP mode, so it may not work for the UP3214Q either) be a kludgy way to get 60 Hz — enable Picture-by-Picture (PBP) in the monitor’s menu and select the DP or mDP and HDMI inputs to be displayed side-by-side (page 36/37 in the manual), connect both DP and HDMI cables to the MBP and try setting both halves of the monitor (which should appear as two separate monitors now) to 1920×2160 at 60 Hz.

 

[Vlade]

Sorry that I haven't replied earlier, but there might (the same-generation Dell UP2414Q is limited to 30 Hz even in PBP mode, so it may not work for the UP3214Q either) be a kludgy way to get 60 Hz — enable Picture-by-Picture (PBP) in the monitor’s menu and select the DP or mDP and HDMI inputs to be displayed side-by-side (page 36/37 in the manual), connect both DP and HDMI cables to the MBP and try setting both halves of the monitor (which should appear as two separate monitors now) to 1920×2160 at 60 Hz.

Nice thinking Amethyst1! I'll give it a try/report when I have time to get the monitor back out and play around (I found a great cyber Monday deal on a similar new monitor which is running at full res/refresh)

 

[Vlade]

Nice thinking Amethyst1! I'll give it a try/report when I have time to get the monitor back out and play around (I found a great cyber Monday deal on a similar new monitor which is running at full res/refresh)

Reporting back on this, no luck. I did get the display to split inputs, but I couldn't get any app to output the right aspect ratio or refresh rate. I did have 60Hz with a few <1080p resolutions, but it was always distorted and the mouse didn't transition nicely from one display to another like you'd expect.

 

[fs454]

I have no issues with my P2715Q from 2015 getting 4K60 out of DP to USB-C (this same monitor cannot do 4K60hz via HDMI) with my M1 Max machine. I previously used it with an Intel 16". I don't believe this monitor is MST like the one you have though and that could be the issue. Like you said though there's definitely many affordable 4K IPS 27-32" monitors out there nowadays if your current setup is doomed. You could probably even score one of these P2715Qs used for dirt cheap too if you didn't want to spend to much. It is funky that it does work on Intel and not with M1 though, but MST is certainly a deprecated protocol so I'm not exactly surprised.