MP 7,1 AMD Radeon Pro W6800X / W6900X MPX Cards - Refresh Rate Crippled?

[LeonPro]

When using the AMD Vega II Pro MPX card under Mac OS or Windows Bootcamp, the maximum refresh rate I can get on a third-party Asus rated at 144Hz Monitor is 100Hz.

Is this the limitation of the Vega II which I'm not convinced since it should be a relatively powerful enough to drive at least 2 x 6K monitors like the XDR.

If I install a third-party Gigabyte 6900XT OC card, thge maximum refresh rate I can get under Mac OS for the Asus 144Hz monitor is also 100Hz. But under Windows Bootcamp, I can get the true 144Hz refresh.

My question is for those who have the W6800X/W6900X MPX cards - what is the maximum refresh you can get for these cards under Mac OS and Windows Bootcamp? I'm afraid the answer will be 100Hz for both OS as it's an Apple driver limitation.

 

[SDAVE]

What kind of cable are you using?

 

[LeonPro]

The same supplied DisplayPort cables by Asus that achieves high refresh rate under Windows Bootcamp but not under Mac OS.

 

[LeonPro]

Anyone with the above card configuration using Bootcamp to confirm what the max refresh rate these can support?

 

[Logix1]

You should be able to get 144hz on Mac OS.
I get 144hz on my Mac Pro with W5700X on Windows 10 and Monterey.
This is the cable I'm using https://www.amazon.com/dp/B06XTYKLNJ?ref=ppx_yo2ov_dt_b_product_details&th=1

 

[LeonPro]

You should be able to get 144hz on Mac OS.
I get 144hz on my Mac Pro with W5700X on Windows 10 and Monterey.
This is the cable I'm using https://www.amazon.com/dp/B06XTYKLNJ?ref=ppx_yo2ov_dt_b_product_details&th=1

Thanks. I can’t get more than 100Hz from the third-party RX 6900XT OC or Vega II MPX under Mac OS.

In Bootcamp, only the 6900XT reaches 144Hz so I’m hoping as you experienced that the newer MPX GPUs have better drivers than the first release GPUs.

 

[MisterAndrew]

Is it possible to determine if the monitor doesn't support that? My monitor is 60 Hz.

 

[LeonPro]

Is it possible to determine if the monitor doesn't support that? My monitor is 60 Hz.

Yes, the monitor needs to support it first and foremost based on its specs.

I have two 32” monitors. One is the XDR with a max refresh rate of 60Hz. The second is an Asus at 144Hz.

In my case both max refresh rates are supported in Bootcamp. Under Mac OS, it’s being crippled to 100Hz.

 

[joevt]

There's probably no way to fix this without some driver patches which may require installing OpenCore, Lilu, and WhateverGreen. The required patches might not exist yet.

Before that, try running AllRez to gather some info about what macOS thinks about your GPU and display.

It's possible that macOS is not enabling DSC which is required for 4K144. You should be able to get 4K120 RGB 8bpc. You may need to create a custom timing in SwitchResX to get that. Another possibility is 4K144 using 4:2:0 10bpc but I don't know if the display supports that and macOS doesn't let you choose color formats.

 

[LeonPro]

There's probably no way to fix this without some driver patches which may require installing OpenCore, Lilu, and WhateverGreen. The required patches might not exist yet.

Before that, try running AllRez to gather some info about what macOS thinks about your GPU and display.

It's possible that macOS is not enabling DSC which is required for 4K144. You should be able to get 4K120 RGB 8bpc. You may need to create a custom timing in SwitchResX to get that. Another possibility is 4K144 using 4:2:0 10bpc but I don't know if the display supports that and macOS doesn't let you choose color formats.

Looking at it, I don't know how to make use of it tbh.