R9-280X 6GB Successful Boot on Mavericks & Snow Leopard

[delToro]

Radeon R9-280X 6GB
GA-x58a-ud3r
24 GB Ram
i7 940
4K LG 40UB8000

1. I successfully upgraded from Snow Leopard to Mavericks 10.9.5
on new SSD. No problem w/ Mavericks.

2. Am booting successfully into previous Snow Leopard drive on the R9-280X 6GB,
but my only resolution choice is 1024 x 768. (Protools w/ Digi 002 is working great
on Snow Leopard/R9 280X but only at 1024x768.)

Question: What DSDT, kext, etc procedure might anyone recommend to boot the
snow leopard drive at more than 1024x768 on the R9-280X, (for Protools / Digi 002).

notes: The snow leopard drive is correctly DSDT/kext configured to a GTX 460, but the GTX 460 is now out of the loop.
Protools version w/ Digi 002 does not configure to Mavericks.

thank you very much

 

[slim.jim]

Florian is probably best to chime in here as he has more experience with AMD cards but I don't think Snow Leopard has the support for a card that came out 2yrs after 10.6.8 was released.

 

[delToro]

Thank you for the reply Slim Jim.
Yes, I agree with you.
I was quite surprised that the Snow Leopard drive even booted up on the R9,
since everything I researched before is no one was having luck even booting on 10.6.8.
And then my Digi002 w/Protools is working flawlessly other than the resolution issue.

In doing more research I see that the R9 280X is just a rebranded HD7970, and there
are reviews of the HD7970 going back as far as 2013.
Though that may actually complicate things because I am certain that Mac
was not programming to Intel yet.

I just thought maybe someone had some advice on where to start experimenting with some
boot flags, kexts, switchres, etc.

Thanks for mentioning Florian, hopefully he finds the time to chime in.
Very much appreciate your response,
thank you,

 

[slim.jim]

Apple switched to Intel long before 2013. Yes the 7970 is the same as a R9 280X but they both came out after the release of 10.6.8.

 

[Fl0r!an]

There's no way to get acceleration on Snow Leopard. Lion in 64bit kernel mode is minimum when using the drivers Sapphire supplied when they released the HD 7950 Mac Edition.

Additionally, I'm quite sure that Snow Leopard can't use GPUs with more than 1GB.