Resolved Sequoia no secondary HDMI output after upgrade

[Bakafish]

I did the Sequoia release upgrade and my second monitor (using HDMI, primary is DP over USB3) wasn't recognized anymore (has been working for the last 5 years.) I tried unplugging and reinserting the HDMI on the display, restarting the Mac Pro and forcing display scan (option key in the display settings pane) but it wasn't recognized. I finally crawled under my desk and changed the HDMI port on the video card (base display, AMD Radeon Pro 580X 8 GB) and that resolved the issue (at least for now anyway.)

Hope this helps someone.

 

[mattspace]

I did the Sequoia release upgrade and my second monitor (using HDMI, primary is DP over USB3) wasn't recognized anymore (has been working for the last 5 years.) I tried unplugging and reinserting the HDMI on the display, restarting the Mac Pro and forcing display scan (option key in the display settings pane) but it wasn't recognized. I finally crawled under my desk and changed the HDMI port on the video card (base display, AMD Radeon Pro 580X 8 GB) and that resolved the issue (at least for now anyway.)

Hope this helps someone.

so you effectively have one dead port? The RX580 should support 3 displays, last I checked. Be curious to see what happens if you plug displays into both hdmi ports, and have nothing in TB.

You're not stuck in safe-mode perchance?

 

[Bakafish]

so you effectively have one dead port? The RX580 should support 3 displays, last I checked. Be curious to see what happens if you plug displays into both hdmi ports, and have nothing in TB.

The DP is routed over a dedicated USB3 port on the Pro's interface card in addition to the pair of HDMI's on the board itself, giving a total of 3 possible ports.

I don't think that specific port is dead, more likely it is HDMI port 2 and the latest Sequoia driver requires something plugged into port 1 before checking port 2. That's just a guess, it's deep under my desk and I don't want to crawl down there and try to read the actual port numbers.

You're not stuck in safe-mode perchance?

No, it was working fine, it just didn't see the secondary display.

 

[mattspace]

The DP is routed over a dedicated USB3 port on the Pro's interface card in addition to the pair of HDMI's on the board itself, giving a total of 3 possible ports.

I don't think that specific port is dead, more likely it is HDMI port 2 and the latest Sequoia driver requires something plugged into port 1 before checking port 2. That's just a guess, it's deep under my desk and I don't want to crawl down there and try to read the actual port numbers.

Hmm, I'd file a bug for that - the system shouldn't require ports to be used in a specific order, it should direct display to whichever ports are connected.

Unless Sonoma has an updated "how to connect x number of Displays to your 2019 Mac Pro" techdoc.