[Success] Radeon RX 6800 XT - Big Sur

[CaseySJ]

Ok. In that case you should at least try to add the device properties what I mentioned above into OC. The memory section is especially important - without it it simply will not boot (along with the agdpmod=pikera - they must be used together). As for b) that is the speed setting of Slot 1 ie. Gen 3/Gen 4 etc. It may come under Max Link Speed under Settings section. As for g) oh it does affect it. Some systems do & don't work with iMacPro1,1, likewise with MacPro20,1 and iMac19,1.

Some things to keep in mind:

• During POST and BIOS, OpenCore is not running. So if there is no DP output during POST and BIOS, it means the problem lies with BIOS or with the monitor.
• Older monitors are generally not recommended. If @emistral is using a monitor that does not support 60Hz over HDMI, it means the monitor is either quite old or it’s a low-end model. It would be best to at least test a current-generation monitor that supports both HDMI 1.2+ and DP 1.2+.
• Because macOS itself has no problem with either DP or HDMI output, it means OpenCore settings are already okay.

 

[StefanAM]

Some things to keep in mind:

• During POST and BIOS, OpenCore is not running. So if there is no DP output during POST and BIOS, it means the problem lies with BIOS or with the monitor.
• Older monitors are generally not recommended. If @emistral is using a monitor that does not support 60Hz over HDMI, it means the monitor is either quite old or it’s a low-end model. It would be best to at least test a current-generation monitor that supports both HDMI 1.2+ and DP 1.2+.
• Because macOS itself has no problem with either DP or HDMI output, it means OpenCore settings are already okay.

RX 6800 XT + samsung odyssey g9: I have same problem with DP. It is a known issue of the monitor. They improve a bit the symptoms with the last monitor firmware, but the solution is to press the menu button on the monitor to keep awake on boot. It is not a bios problem or OS's.

 

[izo1]

If you recently updated to Big Sur 11.3 or 11.4, then it may be necessary to flash a different firmware on the GC-Titan Ridge if the firmware was previously flashed. Specifically, we should flash either the Z390 Aorus Xtreme or Z390 Designare or DSM2 firmware. All of these are available in the Thunderbolt repository.

However, if the original firmware is still installed, then we’ll need to explore other solutions.

Thanks for that, I have the following flashed firmware. I will look into flashing it again.
BTW since I won't be using the TH pin on the mobo or slot 2 anymore, I have connected pin 3 and 5 together, should I keep that modification on the card?

 

[emistral]

Ok. In that case you should at least try to add the device properties what I mentioned above into OC. The memory section is especially important - without it it simply will not boot (along with the agdpmod=pikera - they must be used together). As for b) that is the speed setting of Slot 1 ie. Gen 3/Gen 4 etc. It may come under Max Link Speed under Settings section. As for g) oh it does affect it. Some systems do & don't work with iMacPro1,1, likewise with MacPro20,1 and iMac19,1.

Hi there,

thanks. i'll try. But for info, the system boots, no problem at all. It will boot and load macos. It is just during the POST that there is no video but I know the system is booting.

 

[emistral]

Some things to keep in mind:

• During POST and BIOS, OpenCore is not running. So if there is no DP output during POST and BIOS, it means the problem lies with BIOS or with the monitor.
• Older monitors are generally not recommended. If @emistral is using a monitor that does not support 60Hz over HDMI, it means the monitor is either quite old or it’s a low-end model. It would be best to at least test a current-generation monitor that supports both HDMI 1.2+ and DP 1.2+.
• Because macOS itself has no problem with either DP or HDMI output, it means OpenCore settings are already okay.

Yes the monitor is quite old (2015). It is not a low end, well maybe now it is considered as a low end but at the time it was one of the first 4k@60Hz vi DP in 40" size. But the limitation at the time was HDMI@30Hz which did not bothered me because I have always used it with DP to DP. With the previous card, a 5600 XT same brand, no issue during POST. Only with the 6800XT. Agreed as well that OC has not issue since macos is working fine. I have a 49" dell ultrawide monitor that was bought last year and supports 5k@60hz. I bought it for myself to replace the one that is causing me trouble but due to the pandemic and working from home for a year, my partner decided that it was her monitor now . so either I wait for the pandemic to be over so that I can get the monitor back or I buy a new one

 

[emistral]

RX 6800 XT + samsung odyssey g9: I have same problem with DP. It is a known issue of the monitor. They improve a bit the symptoms with the last monitor firmware, but the solution is to press the menu button on the monitor to keep awake on boot. It is not a bios problem or OS's.

Thanks for the info. Tried it but did not work

 

[Junologue]

Someone wrote that PCIEX3.1 won't take your metal score to above 170k, so i just thought i'd post this to "beg to differ"

MacOS 11.4 RC

Already feel like i want 2 x 6900 XT though, since i work with heavy 3D... =)

 

[CaseySJ]

Thanks for the info. Tried it but did not work

Have you tried enabling CSM Support in BIOS?

 

[CaseySJ]

... I have connected pin 3 and 5 together, should I keep that modification on the card?

Yes, this is still necessary to enable the card when we don't use the Thunderbolt header.

 

[izo1]

Yes, this is still necessary to enable the card when we don't use the Thunderbolt header.

Thank you. Am going to reflash with the firmware you recommended and report back hopefully it will help others.

BTW regarding the TB3 header, if it's in a different slot than the mobo recommended, and if we still use the TB3 header, will it work? Or is the best solution to keep the 3/5 pin mod and remove the TB3 header cable and disable TB3 in the BIOS?