Big Sur install guide?

[SuperheroRobot]

Today I installed a RX 5700 XT and am now trying to do a clean install of Catalina.

 

[Ben42]

Today I installed a RX 5700 XT and am now trying to do a clean install of Catalina.

 

[SuperheroRobot]

The machine wont start up without a GPU. It gives 5 beeps. I think this is a known issue with the motherboard. Should I try installing Catalina with the 1080 attached?

 

[Ben42]

you must specify in the BIOS to use iGPU and connect the monitor to motherboard display port.

 

[SuperheroRobot]

I removed the RX 5700 XT and tried starting the machine without a GPU installed. The machine would not boot up, gave 5 beeps. I installed the GTX 1080 Ti, and the result is the same, Apple logo displays with progress bar, then it restarts. The Catalina installer never loads.

 

[SuperheroRobot]

I set the BIOS to use the integrated GPU, removed the 1080 so no GPUs were installed. The machine did start up, however the result is the same. The Catalina installer never shows up, Apple logo shows with progress bar, then the machine restarts.

 

[pastrychef]

Today I installed a 5700 xt and am now trying to do a clean install of Catalina.

Just make sure you have "agdpmod=pikera" boot argument.

 

[SuperheroRobot]

I tried with Boot Args: dart=0 nv_disable=1 agdpmod=pikera... and this had the same result, Catalina installer never loads and restarts.

dart=0 nv_disable=1 are there by default. Should I remove them?

 

[SuperheroRobot]

I tried booting with agdpmod=pikera with the RX 5700 XT installed. Should I try with the GPU not installed?

 

[SuperheroRobot]

I tried with the GPU installed and removed all Boot Args except for agdpmod=pikera. That had the same result, Catalina doesn't load.

I tried with the GPU uninstalled and with Boot Args: dart=0 nv_disable=1 agdpmod=pikera. This time the Apple logo showed and the progress bar seem to get stuck half way, the machine did not restart. So I decided to restart it and try again in verbose mode. With verbose mode on, Catalina never loaded and the machine restarted.

Does starting in verbose mode ignore the Boot Args?

I tried again with the GPU not installed and with Boot Args: dart=0 nv_disable=1 agdpmod=pikera and verbose off, this time the machine restarted and never loaded the Catalina installer.

And then I tried again with the GPU not installed and with Boot Args: dart=0 nv_disable=1 agdpmod=pikera and verbose off... this time the Apple logo showed and the progress stopped about just under %50... I'm going to wait and see what happens, but as I'm writing this it has already been about 3 minutes and the bar has not moved.