Only 120hz available after macOS 15 upgrade, down from 144hz

[Somian]

I have a M2 Max MacBook Pro 14". I use it with three Gigabyte M32UC Displays. My MacBook Pro is connected via USB-C on both ends.

With macOS 14, I was able to choose 144hz as the display refresh rate.

Now after updating to 15.0.1, I can only select 120hz. It's not a huge issue but I'm wondering why the maximum refresh rate went down 16%...

I didn't change anything else (same cables, same monitors, same MacBook Pro)...

 

[chipsandsalsa]

I have an Gigabyte M32U on an M1 Pro Macbook Pro 14" and these are the options I get. What cable are you using? Is the MBP plugged in as well for max power? I'm using the Apple thunderbolt 3 USB-C cable.

 

[Somian]

I'm using some generic USB 3.2 and USB 4.0 cables. They worked fine before the update. I just updated to 15.1 and I can still only select 120hz.

I just tried a short Apple Thunderbolt cable and it also only gives me 120hz.

What macOS version are you on?

 

[chipsandsalsa]

I'm using some generic USB 3.2 and USB 4.0 cables. They worked fine before the update. I just updated to 15.1 and I can still only select 120hz.

I just tried a short Apple Thunderbolt cable and it also only gives me 120hz.

What macOS version are you on?

I’m on Sequoia 15.1. it could be that you have three monitors plugged in? Maybe a bandwidth issue? Try one monitor at a time and see if you get the 144 Hz back.

 

[Somian]

Same issue with only one display.

And the exact same setup worked at 144hz on macOS 14 🧐

 

[chipsandsalsa]

Thats so strange. I plugged in another monitor at the same time, and even that one shows up as 165hz at the same time. If you're near an Apple store you can try to go there and see if you can plug into a display and if it comes up with the proper refresh rates.

 

[exmophie]

Same issue with only one display.

And the exact same setup worked at 144hz on macOS 14 🧐

Up until MacOS 15.0.1, I had VRR 48-144hz on my 32" Gigabyte 4k HDR (M32U) gaming monitor @ 3360x1890 connected over Thunderbolt 3.

After updating to 15.1, settings are noticeably missing:

HDR, VRR & 144hz modes disappear at resolutions between 2560x1440 and 3840x2160
3008x1692 caps at 120hz fixed
3360x1890 caps at 98hz fixed

It's almost as if my non-Apple display connected over Thunderbolt 3 is somehow being constrained to profiles like a display connected over HDMI 2.1

I'm guessing it's a bug now where if it doesn't see it a known Apple Display profile or some other familiar resolution in an updated plist somewhere it's defaulting the display connection profile down to assume it's 4K TV over HDMI with limitations.

So in 15.1 now it's either 2x retina (1440p) or 1:1 pixel (4K), no scaling in-between resolutions or I lose the display's features, nullifying my choice to go with a display over a 4K TV. Very, very annoying! 🤬

 

[chipsandsalsa]

Is y'alls displays on the newest firmware for the display? I know a few years ago Gigabyte rolled out some USB-C based firmware updates for people who had issues with it. Could be worth checking.

 

[daleski75]

Plugged my 'I should never of spent this much money' M4 Max into my AOC 32" 144hz monitor over USB-C and got 144hz right away.

 

[kiaconchim]

I have an Gigabyte M32U on an M1 Pro Macbook Pro 14" and these are the options I get. What cable are you using? Is the MBP plugged in as well for max power? I'm using the Apple thunderbolt 3 USB-C cable.

View attachment 2449251

Hi I wonder what Cable are you using (as in, the specs of the cable)? I am having the same macbook (16 inch though) and when plugged into my 4k 240hz using Usb-c to DP 1.4 cable, it maxed out at 120hz only, not 144 hz

 

[Somian]

Up until MacOS 15.0.1, I had VRR 48-144hz on my 32" Gigabyte 4k HDR (M32U) gaming monitor @ 3360x1890 connected over Thunderbolt 3.

After updating to 15.1, settings are noticeably missing:

HDR, VRR & 144hz modes disappear at resolutions between 2560x1440 and 3840x2160
3008x1692 caps at 120hz fixed
3360x1890 caps at 98hz fixed

It's almost as if my non-Apple display connected over Thunderbolt 3 is somehow being constrained to profiles like a display connected over HDMI 2.1

I'm guessing it's a bug now where if it doesn't see it a known Apple Display profile or some other familiar resolution in an updated plist somewhere it's defaulting the display connection profile down to assume it's 4K TV over HDMI with limitations.

So in 15.1 now it's either 2x retina (1440p) or 1:1 pixel (4K), no scaling in-between resolutions or I lose the display's features, nullifying my choice to go with a display over a 4K TV. Very, very annoying! 🤬

Interesting.

I don't know if it would still work with 15.0.1, because I "upgraded" right from macOS 14 to 15.1.

 

[chipsandsalsa]

Hi I wonder what Cable are you using (as in, the specs of the cable)? I am having the same macbook (16 inch though) and when plugged into my 4k 240hz using Usb-c to DP 1.4 cable, it maxed out at 120hz only, not 144 hz

Apple Thunderbolt 3 USB-C cable, 0.8m length.

 

[Danborg]

Was this ever resolved? I'm having the exact same issue.

 

[Danborg]

I got this working by upgrading the firmware on the M32UC *and* switching to a high quality HDMI cable using the built in HDMI port on my 14" MacBook Pro -- previously I was using a USB-C to DisplayPort cable, but something has changed with the OS such that now it "favors" the HDMI port and only gives me fully capabilities when using that. No big deal -- in fact, this frees up a USB-C port now that was previously consumed, so this is more optimal.
(P.S. Do you know how hard it was to find a USB cable with a Type-B connector in 2024?! That's what is needed to update the firmware on the monitor. Sheesh.)

 

[AppelGeenyus]

It’s 100% a macOS 15 issue, everyone experiencing the issue should report it in feedback assistant.

Also anyone that still has working 120hz+ in macOS 15 should check if you are still getting full 4:4:4 rgb, several people I’ve spoken to(and including myself) are now capped at 4:2:2 chroma, and 4:4:4 only works at 95hz or less.

 

[throAU]

Confirming I used to be able to select 144hz on my monitor and now only 120hz.

Also pretty sure I could also do 144/hdr and hdr is now limited to 60hz on same hardware/cable (apple thunderbolt4 cable)