MP 1,1-5,1 Problem with 5,1 and RX 580?

[LookToWindward]

Hi,

I have a Mac Pro 5,1 with an RX 580 running OC/Monterey. I did have an HDMI monitor and a DVI monitor connected to the RX 580. Today I got a new 32 Inch monitor and have set it up with the new monitor on DP and the other on HDMI. The new one works on DP fine but I can't get anything on the HDMI port? Any ideas on how to fix this?

The 580 is a Mac Radeon.

Thanks a lot

 

[LookToWindward]

I've tried reseting NVRAM and lowering the resolution, still nothing. If I look at the System Report is just show the one monitor on the DP port. I've tried it with both DP ports, same problem

 

[reader50]

I've had trouble using some HDMI displays (usually TVs) with my classic Macs. I suspect some low-cost TVs are demanding recent HDCP implementations. HDCP should be optional when used with an unencrypted source like a graphics card.

Anyway, my solution is to insert an active adapter. This one made my HDMI TV happy. Other HDMI TVs are not bothered, and just work directly.

 

[bmoraski]

Make sure you have a newer hdmi cable.

 

[LookToWindward]

The HDMI cable was working perfectly when I had HMDI + DVI so why should it not be up to HDMI + DP?

 

[LookToWindward]

I've had trouble using some HDMI displays (usually TVs) with my classic Macs. I suspect some low-cost TVs are demanding recent HDCP implementations. HDCP should be optional when used with an unencrypted source like a graphics card.

Anyway, my solution is to insert an active adapter. This one made my HDMI TV happy. Other HDMI TVs are not bothered, and just work directly.

Not a TV it's a Samsung 24 Inch and it was working ok with HDMI + DVI

 

[reader50]

Do you have a DP -> HDMI cable available? In most cases, new monitor combinations just work. When they don't, I try alternate cables and/or adapters.

You might try a PRAM reset, or even an SMC reset. Neither should be needed to accept a new monitors combination, but it's easy to test.

You could even try connecting all three monitors and reboot. If they all come up working, disconnect the old DVI monitor. Perhaps Monterey will take the hint and keep the HDMI monitor working.