RX 6900 XT in Mac Pro 5,1

[gogavik]

Dear all,

I have a Mac Pro 5,1, 2x X5690, 48GB ram with Pixlas mod, Opencore & Big Sur 11.6, NVME boot disk, Nvidia GTX680 all working perfect
Checked the support for AMD 6XXX but after inserting the AMD RX6900XT, the mac pro does not boot, all lights on
Big sur with OpenCore should support the GPU but does anybody know if the hardware of Mac Pro 5,1 does support the latest AMD GPU's?

Regards,
Rob

 

[Feartech]

Dear all,

I have a Mac Pro 5,1, 2x X5690, 48GB ram with Pixlas mod, Opencore & Big Sur 11.6, NVME boot disk, Nvidia GTX680 all working perfect
Checked the support for AMD 6XXX but after inserting the AMD RX6900XT, the mac pro does not boot, all lights on
Big sur with OpenCore should support the GPU but does anybody know if the hardware of Mac Pro 5,1 does support the latest AMD GPU's?

Regards,
Rob

i have moved your post to Mac Pro forum

 

[gogavik]

Dear All,

topic can be closed, found root cause.

the 6900 need AVX to boot and the CPU series in MAC PRO 5,x does not support that.

not sure if allowed but here is the explanation the AMD 6xxx series will not boot in the MAC PRO 5,x

AMD Radeon RX 6800 XT / 6900 XT for macOS?

Update: As @Syncretic points out below, this analysis is incorrect. The Intel firmware image does not use AVX instructions. CONFIRMATION: The Radeon RX 6800 / 6900 series EFI uses AVX instructions I downloaded the VBIOS file for the reference design RX 6800 from the TechPowerUp site. I opened...

forums.macrumors.com

the max card for the Mac Pro will be the AMD 5XXX series.

regards,
rob

 

[zirkaiva]

Dear All,

topic can be closed, found root cause.

the 6900 need AVX to boot and the CPU series in MAC PRO 5,x does not support that.

not sure if allowed but here is the explanation the AMD 6xxx series will not boot in the MAC PRO 5,x

AMD Radeon RX 6800 XT / 6900 XT for macOS?

Update: As @Syncretic points out below, this analysis is incorrect. The Intel firmware image does not use AVX instructions. CONFIRMATION: The Radeon RX 6800 / 6900 series EFI uses AVX instructions I downloaded the VBIOS file for the reference design RX 6800 from the TechPowerUp site. I opened...

forums.macrumors.com

the max card for the Mac Pro will be the AMD 5XXX series.

regards,
rob

That is not correct. Look down that thread at the end. People booted 6800XT successfully.

 

[gogavik]

That is not correct. Look down that thread at the end. People booted 6800XT successfully.

yes, you are right, they found a solution for that in the meantime by flashing the card. when I got it in 2021 it wasn't there yet. actually, looking at it now.