9070 XT - 2x HDMI high refresh displays (144 and 120 Hz) not working

[King Mustard]

ASRock B650M Pro RS
AMD Ryzen 7 7800X3D
32 GB DDR5-6000
Corsair RM850x (2018) 850W PSU (manual)

I have just bought an RX 9070 XT, which will replace my RTX 3080.

I used the same PSU cable that I used with the RTX 3080 (page 6 of the manual, labelled 'PCIe 8 pin (6+2) cable').

I used Safe Mode and DDU to remove the NVIDIA drivers, and also used Safe Mode to install the latest Adrenalin v25.3.1 drivers.

I have a primary LG C4 (HDMI only) (144 Hz) and a secondary LG C2 (HDMI only) (120 Hz).

The RTX 3080 only had 1x HDMI port, so I used an active DP-HDMI adapter with the LC C2 and it all worked fine (144 Hz on the LG C4 and 120 Hz on the LG C2).

My new RX 9070 XT has 2x HDMI ports, so I was hoping to skip needing the DP-HDMI adapter.

When I connect the LG C4 on its own, it detects 144 Hz in Windows and I can play games with no problems - they run as exactly as they should (i.e. far quicker than the RTX 3080 did).

As soon as I connect the LC C2 (via HDMI), AMD's drivers say there are driver hangs (or something to that effect) and within a few seconds, the system locks up.

If I try to connect the LC C2 via DP (via that adapter), Windows detects it and I can use it a second display - but Windows is now detecting it only as having a max of 60 Hz (instead of 120 Hz that the display is capable of). When I try to force 120 Hz, I just get a black screen on the LG C2.

I am starting to already regret leaving NVIDIA.

Can anyone please assist?

 

[King Mustard]

Not sure. Are you using hdmi 2.1 certified cables?

Did you use 2 of those cables from PSU? Not a single, with the two connectors, as that is a no no.

They are and they worked perfectly with the RTX 3080. The issues only occured since plugging in the RX 9070 XT.

I only used one of the cables, as that worked with the RTX 3080. Will try two now.

I seem to remember one of the 9070xts (you don't say which model you have?) with dual HDMI outputs will only do two outputs at a reduced bandwidth. This would make sense if they both share one bus header.

Does your old DP cable still work?

It is the Sapphire Pulse. Unfortunately, it would not explain why I cannot get 120 Hz on the LC C2 (secondary) with the HDMI-DP adapter, like I could with the RTX 3080.

I do not have a DP cable as the TV does not support DP. I used an active HDMI-DP adapter, which worked perfectly with the RTX 3080.

 

[King Mustard]

Unfortunately, using two PCIe PSU cables did not change anything.

 

[King Mustard]

I meant that - I see now you've tried using your old setup and that doesn't work.

Very strange. Are you changing refresh rate in Windows? Have you tried changing it in Adrenalin? It might not work but it may reveal a bit more info.

Unfortunately, there do not appear to be any extra hints there.

 

[King Mustard]

Nothing silly like gsync still set up on the monitors?
Reset the monitors to defaults. Disable gsync

The 'VRR & G-Sync' option is turned off on the TVs.

I just tried factory-resetting the LG C2 (secondary display), to no avail, unfortunately.

could be an issue with the adapter? are the monitors on default settings?

It worked perfectly an hour ago, with the RTX 3080.

I just tried factory-resetting the LG C2 (secondary display), to no avail, unfortunately.

 

[King Mustard]

I've had all these issues with various AMD cards.

I've also found in the past that AMD cards might perhaps be more picky with cables and such as I've had Nvidia cards that can run 120/144hz but using an AMD card with the same cable and monitor it's limited to 60hz.

I've said a few times that I was unable to use both HDMI ports at the same time. If your issue is like mine then both ports work fine separately but not together.
What resolution are your displays? I've had this when using 4K (120Hz) displays. From what I've read it's possible that despite having 2 HDMI ports they share bandwidth. So it might be that each display needs more than half the available bandwidth?

Also have an Nvidia card with 2 HDMI port that doesn't have the issue. The AMD card was a Sapphire Pulse and the Nvidia card was a Gigabyte, so I'm not sure if it's an AMD thing or a Sapphire thing.

I have tried with the HDMI-DP active adapter though (that supports 4K120 and worked at 4K120 with the RTX 3080) and it is stuck at 4K60 on the RX 9070 XT.

 

[King Mustard]

Not sure. Are you using hdmi 2.1 certified cables?

Did you use 2 of those cables from PSU? Not a single, with the two connectors, as that is a no no.

It is (was) this: www.amazon.co.uk/dp/B08BRZXCNH

I cannot find a UK list of 1.8m-2.0m certified HDMI 2.1 cables that are available inside the UK. A Google search only really brings up Kenable cables, and they could be lying for all I know

I got the Amazon one, because a few years ago, Linus (LTT) tested many and I am sure I remember Amazon Basics ones being valid/good.

 

[King Mustard]

@AMD_Vik Sapphire Pulse.

I appreciate it.

 

[King Mustard]

I was thinking of picking a 9070XT for the 2x HDMI so that's me out then.

Was Gsync working at 4k/120hz + HDR with your DP-HDMI adapter? Which adapter is that?

All of that worked.

https://www.cablematters.com/pc-1385-154-displayport-14-to-8k-hdmi-adapter.aspx

 

[King Mustard]

If it helps I asked AI and it said:

The AMD Radeon RX 9070 XT GPU supports up to four displays, with a maximum resolution of 7680×4320 for both HDMI 2.1 and DisplayPort 2.1a outputs. When connecting two HDMI 2.1 displays, each should theoretically be able to run at 4K resolution (3840×2160) with refresh rates up to 120Hz.

So if you have your LG C4 connected, that is a 4K display. Can you drop the refresh rate in Windows to 120Hz (don't pick 144Hz), and then connect the LG C2? Then in theory as that is 4K as well it should allow you to set 120Hz.

Same issue unfortunately - display driver crashes and does not recover (even with Win + Ctrl + Shift + B).

I have some certified cables coming from kenable. Hopefully they help.

If it does end up that the GPU can only do 2x 120 Hz displays on the header when my five-year-old RTX 3080 can drive higher (and with less issues), it is far from a good look for AMD.

 

[King Mustard]

Use an active hdmi-to-dp adapter? If the dp2.1 sockets can handle 4K 120Hz then no need to use both hdmi sockets.

I would prefer two straight HDMI connections.

The adapter, for example, can be sensitive to static in the room and make the display flicker at times.

Plus, I imagine not using an adapter is almost always better than using one.

Either way, the display using the adapter (or even straight HDMI) will not exceed 60 Hz (even though it was perfectly fine on the RTX 3080).

I have two new certified HDMI cables on the way, to see if it helps.

 

[King Mustard]

My money is on driver issues. It's only been out a couple of days, so further revisions may sort this.

That is a fair point.

 

[King Mustard]

Thanks for bringing this up. I'll file this through and see what we can learn. Could you please search your system for 'atikmdag_dce.log' and send that over to me along with any relevant minidmp files over at C:\Windows\Minidumps\ or at C:\Windows\LiveKernelReports\WATCHDOG\ in the mean time.

What is the best way to get them to you?

 

[King Mustard]

DM me perhaps, use something like https://send.vis.ee/

All done