4k 144Hz no longer available after upgrade to Big Sur

#1

Post by FireBeyond » Wed, Dec 16, 2020, 12:06 AM UTC

4k 144Hz no longer available after upgrade to Big Sur
egpu.io

Re: 4k 144Hz no longer available after upgrade to Big Sur

#2

Post by FireBeyond » Wed, Dec 16, 2020, 12:10 AM UTC

Happened to me. With Catalina, my Mac Pro (2019, W5700X) was able to drive 2 LG 27GN950-B 27" monitors at 4K, 144Hz, HDR.

Under Big Sur? 60Hz only, for HDR, or 95Hz without HDR. It seems Display Stream Compression (DSC) is broken in Big Sur, including 11.1, including for some Apple display users. For other users, doesn't matter the display, the GPU, or the cable, this seems broken.

Apple gets bit (again) by the WFM bug.

Multiple people report having spoken to Apple who has said "Macs max out at 95Hz", though it is unclear where the confusion may be there (perhaps the M1), as they definitely don't under Catalina.

Re: 4k 144Hz no longer available after upgrade to Big Sur

#3

Post by fortran77 » Wed, Dec 16, 2020, 12:44 AM UTC

It's nice to have options on Windows 10 and a choice of GPU and driver vendors.

Re: 4k 144Hz no longer available after upgrade to Big Sur

#4

Post by teach » Wed, Dec 16, 2020, 12:45 AM UTC

fortran77 wrote: post #3

It's nice to have options on Windows 10 and a choice of GPU and driver vendors.

You misspelled Ubuntu.

Edit: I don't know what I expected.

Re: 4k 144Hz no longer available after upgrade to Big Sur

#5

Post by da_big_ghey » Wed, Dec 16, 2020, 12:51 AM UTC

teach wrote: post #4

fortran77 wrote: post #3

It's nice to have options on Windows 10 and a choice of GPU and driver vendors.

You misspelled Ubuntu. Edit: I don't know what I expected.

You misspelled Archlinux.

Re: 4k 144Hz no longer available after upgrade to Big Sur

#6

Post by EGreg » Wed, Dec 16, 2020, 12:52 AM UTC

da_big_ghey wrote: post #5

teach wrote: post #4

Earlier quoted context omitted.

You misspelled Ubuntu. Edit: I don't know what I expected.

You misspelled Archlinux.

You misspelled whatever is here https://xkcd.com/378/

Re: 4k 144Hz no longer available after upgrade to Big Sur

#7

Post by acuozzo » Wed, Dec 16, 2020, 12:52 AM UTC

fortran77 wrote: post #3

It's nice to have options on Windows 10 and a choice of GPU and driver vendors.

My Windows 10 installation forcibly rebooted to install updates right in the middle of a 10+ hour overnight render.

Re: 4k 144Hz no longer available after upgrade to Big Sur

#8

Post by zackify » Wed, Dec 16, 2020, 12:53 AM UTC

da_big_ghey wrote: post #5

teach wrote: post #4

Earlier quoted context omitted.

You misspelled Ubuntu. Edit: I don't know what I expected.

You misspelled Archlinux.

You misspelled PalmOS

Re: 4k 144Hz no longer available after upgrade to Big Sur

#9

Post by backing » Wed, Dec 16, 2020, 12:54 AM UTC

da_big_ghey wrote: post #5

teach wrote: post #4

Earlier quoted context omitted.

You misspelled Ubuntu. Edit: I don't know what I expected.

You misspelled Archlinux.

You misspelled c++.

Re: 4k 144Hz no longer available after upgrade to Big Sur

#10

Post by shmoogy » Wed, Dec 16, 2020, 12:55 AM UTC

FireBeyond wrote: post #2

Happened to me. With Catalina, my Mac Pro (2019, W5700X) was able to drive 2 LG 27GN950-B 27" monitors at 4K, 144Hz, HDR. Under Big Sur? 60Hz only, for HDR, or 95Hz without HDR. It seems Display Stream Compression (DSC) is broken in Big Sur, including 11.1, including for some Apple display users. For other users, doesn't matter the display, the GPU, or the cable, this seems broken. Apple gets bit (again) by the WFM b…

My m1 air does 5120x1440 @ 120hz, so they cannot cap out at 95hz.