MP 1,1-5,1 MSI RX6600 MECH 2X 8G Won't Work

[John Fu]

Hello all,

I just replaced my RX5700 with MSI rx6600 mech 2x 8g, and it can not even boot up, I put in another original Apple display card together, and I can hear the sound, the system keeps looping it, is this rx6600 mech 2xn 8g did not work with Monterey or should I need to flash the bios to 6600?

Thank you

 

[tsialex]

All Navi 2x GPUs are incompatible with MacPro5,1 unless previously patched:

AMD Radeon RX 6800 XT / 6900 XT for macOS?

By design, the Mac Pro EFI BootROM uses UGA (an older standard) for screen output. Mac-compatible cards provide UGA, which lets you see the native boot picker and the early boot screens (before MacOS loads). Without a UGA-compatible card (i.e. with non-Mac/PC cards), you'll see a black screen...

forums.macrumors.com

A NAVI 2x GPU with unpatched firmware will not let the Mac Pro complete POST/boot anything.