SOLVED : Strange visual glitches after install

[lucB]

Hi (Sorry for my average English)
I've installed Catalina 10.15.7 on a new hardware (below) :

I have now very annoying screen glitches :

• some random horizontal noise lines
• every 1 to 4 seconds flashing white rects at the bottom of the screen
• every say 10 to 30s a black screen the screen comes down after 1 to 3 s.
• in control panel / screen, if I don't choose default and try to lower or upper the initial resolution, the dock at the bottom moves very fast between 2 difference positions

BTW: as my RX580 is in compute mode, for unknown (for me) reason, the system forces CSM on (the guide says CSM off) and I can't put it off
Just to try : I added in boot args : -agdpmod =pikera, it didn't help.....

Someone could help me ? (please)
I used the Dortania install guide and openCore 0.6.3 and doublechecked my actions

My hardware :
AMD 3950x, 32Go RAM,
Asus ROG STRIX B450-I GAMING ITX bios 3004 (fairly recent one)
Sapphire pulse RX580 8Go V2 (dual boot) in compute mode
Samsung 970 EVO plus NVM2 M.2 2TO
Case Fractal Node 304,( my goal was / is to build a very powerful yet compact system ).

My bios settings :
EveryThing to Auto
some parameters were not visible (ex. above4GDecoding), so I added the boot options required I think following the guide
I tried to put CSM off but at boot, it's re forced On
Fast Boot disabled
Secure Boot : I've tried UEFI Windows mode and Other OS, no changes
I've no clue of what happens...

I would really really appreciate if someone would care. I must have made a noob mistake somewhere....

I attached my EFI :
Any help would be greatly appreciated....

EDIT :
I solved it by simply using a displayPort cable.
My problem was using HDMI out of the RX580 to 4K screen
Strange, because first thing if did was testing separately each component rx580, HDMI cable to non 4K monitor, then same cable+ 4K monitor and another PC, etc. all of this was working
Well anyway, as it works with DP, problem solved even it I don't understand everything....


Best regards. LucB

 

[acasas]

did you figure out how to get a better performance ?

 

[Gigamaxx]

Check your config.plist in Open Core Sanity Checker.

1. SetVirtualMap =Yes should be NO.
2. ROM =112233000000, set to correct Open Core configurator can set these for you automatically.

 

[lucB]

Check your config.plist in Open Core Sanity Checker.

1. SetVirtualMap =Yes should be NO.
2. ROM =112233000000, set to correct Open Core configurator can set these for you automatically.

thank you Gigamaxx for the config.plist remarks.

I solved my screen problem by simply using a displayPort cable.
My problem was using HDMI out of the RX580 to 4K screen
Strange, because first thing if did was testing separately each component rx580, HDMI cable to non 4K monitor, then same cable 4K monitor with another PC, etc. all of this was working
Well anyway as it works with DP, problem solved

I hesitate to change the SetVirtualMap parameter as in the Dortania 0.6.3 they say "Note B550, A520 and TRx40 boards should disable this. Newer BIOS versions of X570 also require this off" and my board is a B450
Yes the ROM parameter not set is perhaps the origin of my "WIFI not configured" (strange because WIFI and BY worked OOB, I swapped the card for a BCM94360NG)

For now, everything seems to globally work (message, wifi, BT) except perhaps sleep / hibernate I still have to check
and every minute short sudden ramp up fan noises issues even after bios modifications ( 30s ramp up delay, custom param, etc...))
Geekbench5 around 1320 single / 11580 multicore which doesn't seem ridiculous....