Hello good people!
 
I've just got a new Z690 Classified and I'm trying to load a live CD distro with GSAT (Google Stress Application Test) to figure out if my memory is stable and OK, but for that I need to boot of a non UEFI usb disk.
 
Usually I've do into the BIOS and enable CSM, but when I do this I get a warning that the internet GPU is not supported in non UEFI mode... OK I have an RTX 3090 (not using the IGD/Intel Graphics). But as soon as I reboot with these settings I get a d6 error on the board (graphics cards not found). I even tried explicitly disabling IGD and enabling only PEG (PCI Express Graphics) but still the same problem.
 
I'm running a 12900K with 2x32GB G Skill 6000 CL36 RAM. As the PEG I have an EVGA RTX 3090 FTW3.
 
I can run Memtest 9.4 in UEFI mode - which incidentally reports the wrong settings for the memory (showing as 4806MHz / 40-40-40-77, when I've set XMP on the BIOS and it should be 6000MHz / 36-36-36-79). I think it's wrong as if I set the memory to AUTO in the BIOS I get 21.7GB/s, but when I set at XMP I get 26GB/s... so I'm assuming that Memtest is just reading the first profile and not the actual one being used.
 
Anyway, back to the CSM question? has anyone used CSM with this board? Did it work?
 
Cheers!
 
 

I have not! Good idea… I’m trying to recreate the GSAT distro with UEFI, if I don’t succeed I’ll try this…

I ended up recreating the GSAT distro with UEFI booting so didn't need to try enabling CSM in the end. But you might be right, maybe I needed to disable resizable bar support as well to get it to work initially. I had assumed that once you selected CSM the BIOS would automatically disable that, but may be not...