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

King Mustard

King Mustard

King Mustard

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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?
 
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.
 
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?
 
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Firegod said:
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.
Click to expand...
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.

Bidley said:
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?
Click to expand...
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.
 
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King Mustard said:
It is the Sapphire Pulse.

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.
Click to expand...
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.
 
Bidley said:
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.
Click to expand...
Unfortunately, there do not appear to be any extra hints there.
 
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King Mustard said:
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.


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.
Click to expand...
could be an issue with the adapter? are the monitors on default settings?
 
Subliminal Aura said:
Nothing silly like gsync still set up on the monitors?
Reset the monitors to defaults. Disable gsync
Click to expand...
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.

Tythus said:
could be an issue with the adapter? are the monitors on default settings?
Click to expand...
It worked perfectly an hour ago, with the RTX 3080.

I just tried factory-resetting the LG C2 (secondary display), to no avail, unfortunately.
 
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.
 
GoogalyMoogaly said:
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.
Click to expand...
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.
 
Firegod said:
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.
Click to expand...
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.
 
Not sure if this is the case but have you tried disabling MPO? Once my sibling switched from Nvidia to AMD (with fresh install of win11) immediately start getting issues on his secondary monitor. (stuttering videos, artifacts over display etc)

With quick research end up with this solution. Not sure what to do physically but it worked. You can always delete the key. Harmless to try.

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\Dwm] "OverlayTestMode"=dword:00000005
 
King Mustard said:
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.
Click to expand...
Looks OK but I guess it doesn't say certified. Hmm. Up to you, certainly is an odd issue, but if you'd like to change out to a certified cable then I use startech hdmi and dp cables. You can get 2m 2.1 certified if you Google "startech HDMM21V2M". Here is the product page https://www.startech.com/en-gb/cables/hdmm21v2m

Good luck.
 
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?
 
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