MP 1,1-5,1 Upgraded GFX card issues—a catch 22

[eicca]

Just picked up a cMP 2010. It’s got a Sapphire Radeon RX 580 in it, which works fine, with one issue: if the stock GeForce GT 120 is installed as well, the fans go berserk.

If I remove the GeForce, the fans run at correct speeds, but the computer won’t boot.

How am I supposed to install Mojave if the installer won’t run with the GeForce still in the computer, but the computer won’t boot without the GeForce?

Help. I’m already in over my head.

 

[Ludacrisvp]

It will boot just wait longer

 

[Macsonic]

Just picked up a cMP 2010. It’s got a Sapphire Radeon RX 580 in it, which works fine, with one issue: if the stock GeForce GT 120 is installed as well, the fans go berserk.

If I remove the GeForce, the fans run at correct speeds, but the computer won’t boot.

How am I supposed to install Mojave if the installer won’t run with the GeForce still in the computer, but the computer won’t boot without the GeForce?

Help. I’m already in over my head.

You'll need to have High Sierra installed first before you could install Mojave. For 2010 cMac Pros it's the requirement Apple mentioned.

Install macOS 10.14 Mojave on Mac Pro (Mid 2010) and Mac Pro (Mid 2012) - Apple Support

Learn how to prepare your Mac Pro (Mid 2010) or Mac Pro (Mid 2012) for macOS Mojave.

support.apple.com

 

[tsialex]

You'll need to have High Sierra installed first before you could install Mojave. For 2010 cMac Pros it's the requirement Apple mentioned.

Install macOS 10.14 Mojave on Mac Pro (Mid 2010) and Mac Pro (Mid 2012) - Apple Support

Learn how to prepare your Mac Pro (Mid 2010) or Mac Pro (Mid 2012) for macOS Mojave.

support.apple.com

It's a requirement for a Mac Pro without the current firmware, a Mac Pro needs to be updated to MP51.0089.B00 then to 144.0.0.0.0.

Once you have BootROM 144.0.0.0.0 already installed, you can install Mojave without High Sierra.

MP5,1: What you have to do to upgrade to Mojave (BootROM upgrade instructions thread)

Please fully read this first post, you will probably find that you have one or more problems described into the various notes below. Mojave will only install if you have upgraded your BootROM to the current release and your Mac Pro have a Metal capable GPU*. If you are trying to install Mojave...

forums.macrumors.com

 

[Macsonic]

It's a requirement for a Mac Pro without the current firmware, a Mac Pro needs to be updated to MP51.0089.B00 then to 144.0.0.0.0.

Once you have BootROM 144.0.0.0.0 already installed, you can install Mojave without High Sierra.

MP5,1: What you have to do to upgrade to Mojave (BootROM upgrade instructions thread)

Please fully read this first post, you will probably find that you have one or more problems described into the various notes below. Mojave will only install if you have upgraded your BootROM to the current release and your Mac Pro have a Metal capable GPU*. If you are trying to install Mojave...

forums.macrumors.com

Thanks for the important info on the firmware update prerequisite, tsialex This clears up things.

 

[eicca]

From the sounds of it Mojave was already installed once but rolled back for some reason. The machine is currently on High Sierra but the bootROM is 140.0.0.0.0.0.0.0.0. Or whatever.

Also, don’t know exactly what caused things to work but I reset the SMC and PRAM three times and now it’s running on the Radeon alone just fine with quiet fans. Mojave installer loads properly now.