MP 1,1-5,1 MP5.1 with Legacy + Polaris GPU

[Leborgne23]

Hi,
A customer of mine used to work with OSX 10.7 on his MP5.1 but now needs macOS 12 on top of that.
His GPU is the ATI Radeon HD 5770 that came with it back in 2010.
I used OC legacy patcher to install macOS 12 and add support for his non-metal GPU but some programs like Logic Pro X do require a true Metal compatible GPU (glitches or missing GUI elements without one).
I made him buy a Polaris GPU (RX560) to be able to work around that but now here is what I'm stuck with :

1 - although the install process went well, macOS 12 won't boot with both GPU's physically installed (stuck midway).
2 - physically removing the legacy GPU solves the issue but obviously OSX 10.7 won't work with a Polaris GPU.
3 - removing the Polaris GPU and root patching macOS 12 for legacy GPU support makes the system bootable with both GPU installed but only the legacy GPU works (the Polaris GPU is shown in system report but no kext is loaded)
4 - Disabling the legacy GPU by using the "device properties method" has no effect whatsoever and I'm discouraged to try the SSDT method.

Here's a recap of what my customer wants :
- Being able to boot OSX LION by pressing Alt and using the Apple boot picker.
- Being able to boot macOS 12 without the hassle of opening the case to remove the legacy GPU.

Anyone with an idea of what I should try next ?
Thanks

 

[Macschrauber]

Have you tried booting 10.7 with OpenCore (by adding -no_compat_check to the boot-args in open core config) and Polaris GPU. Some Apps work with just framebuffer support.

2nd thing you can try with Polaris and 10.7: adding a Bootscreen to the Polaris GPU by either adding EnableGop to the GPU or the Mac firmware. And running 10.7 thru framebuffer support and the native boot picker.

 

[Leborgne23]

Have you tried booting 10.7 with OpenCore (by adding -no_compat_check to the boot-args in open core config) and Polaris GPU. Some Apps work with just framebuffer support.

2nd thing you can try with Polaris and 10.7: adding a Bootscreen to the Polaris GPU by either adding EnableGop to the GPU or the Mac firmware. And running 10.7 thru framebuffer support and the native boot picker.

Thanks ! definitely worth a try.

 

[h9826790]

Flash the cMP with EnableGop is a work around (IMO, you should do this whenever plan to install RX580 regardless has this issue or not). However, in this case, any software in 10.7 that need GPU power won't work. I doubt if your client can really accept that (If he only need some very basic function in 10.7. Then most likely he doesn't even need 10.7 now, but can move on. If he stuck with 10.7 because of some legacy software, then very likely he need a GPU that can provide acceleration in 10.7).

If you can install both GPU into the cMP. My suggestion is to learn how to disable a GPU via OpenCore. So that you can disable the 5770 in OpenCore (e.g. via SSDT).

Therefore, when your client boot the computer. It's defaulted to boot to OpenCore, which can then bridge boot to Monterey with 5770 disabled. In this case, the RX580 will do all the work.

When he need 10.7. He hold option to boot and select 10.7. Then the 5770 should work, and 10.7 should ignore the existence of RX580 (apart from that the RX580 will still draw quite a bit of power). With EnableGop, the RX580 can even still provide basic display function in 10.7.

I don't know how many monitors he use, but if only one, then he can connect both 5770 and RX580 to the same monitor. So that the same monitor can work with both cards in both OS.

 

[Leborgne23]

Flash the cMP with EnableGop is a work around (IMO, you should do this whenever plan to install RX580 regardless has this issue or not). However, in this case, any software in 10.7 that need GPU power won't work. I doubt if your client can really accept that (If he only need some very basic function in 10.7. Then most likely he doesn't even need 10.7 now, but can move on. If he stuck with 10.7 because of some legacy software, then very likely he need a GPU that can provide acceleration in 10.7).

If you can install both GPU into the cMP. My suggestion is to learn how to disable a GPU via OpenCore. So that you can disable the 5770 in OpenCore (e.g. via SSDT).

Therefore, when your client boot the computer. It's defaulted to boot to OpenCore, which can then bridge boot to Monterey with 5770 disabled. In this case, the RX580 will do all the work.

When he need 10.7. He hold option to boot and select 10.7. Then the 5770 should work, and 10.7 should ignore the existence of RX580 (apart from that the RX580 will still draw quite a bit of power). With EnableGop, the RX580 can even still provide basic display function in 10.7.

I don't know how many monitors he use, but if only one, then he can connect both 5770 and RX580 to the same monitor. So that the same monitor can work with both cards in both OS.

Hi !
Well I went through GPU disabling via the SSDT method and unfortunately this did not do the trick.
Regardless of having the Polaris GPU installed or not I'm stuck at the very beginning of macOS 12 loading.
I only have the Apple logo, no progress bar, no activity from the SSD and no image whatsoever on the Polaris GPU.
In case someone wants to check it out here's my EFI folder. tsiAlex warned me that using OC Legacy patcher would be detrimental instead of helpful but I only know this tool.
Thanks for your help.

 

[Leborgne23]

Have you tried booting 10.7 with OpenCore (by adding -no_compat_check to the boot-args in open core config) and Polaris GPU. Some Apps work with just framebuffer support.

2nd thing you can try with Polaris and 10.7: adding a Bootscreen to the Polaris GPU by either adding EnableGop to the GPU or the Mac firmware. And running 10.7 thru framebuffer support and the native boot picker.

Thanks for that advice but my customer needs acceleration in OSX 10.7, not just framebuffer support.

 

[flaubert]

I think that your simplest, most direct solution would be to buy a second cMP 5,1. Your customer already has acquired the single most expensive component, namely the second GPU card. You're just asking a lot to make a single machine stretch that far back in compatibility, especially if you're using a pre-configured solution like OCLP.

 

[Macschrauber]

Thanks for that advice but my customer needs acceleration in OSX 10.7, not just framebuffer support.

Have you tried the apps he uses? Those old systems run surprisingly well just on framebuffer.

 

[h9826790]

Hi !
Well I went through GPU disabling via the SSDT method and unfortunately this did not do the trick.
Regardless of having the Polaris GPU installed or not I'm stuck at the very beginning of macOS 12 loading.
I only have the Apple logo, no progress bar, no activity from the SSD and no image whatsoever on the Polaris GPU.
In case someone wants to check it out here's my EFI folder. tsiAlex warned me that using OC Legacy patcher would be detrimental instead of helpful but I only know this tool.
Thanks for your help.

Then the next "hard way" to work around this problem will be install Linux.

Boot to Linux, use QEMU to run Monterey in VM. And only PCIe passthrough the RX580 into the VM.

Which means, your client can boot 10.7 natively.

When want to use Monterey, boot to Linux, then start the Monterey VM. There will be a little bit performance hit, but should be very insignificant.

 

[Leborgne23]

Have you tried the apps he uses? Those old systems run surprisingly well just on framebuffer.

Well @Macschrauber you are absolutely right ! I made the decision to flash the MP's firmware with the addition of the EnableGop driver and I 'm pleased to report that OSX LION and Logic Pro 9 both run fine without actual GPU acceleration. I was fearing the same sluggishness as when I tried to run Big Sur on my 6800XT before official RDNA2 support months later. That's not teh case at all, I see no performance hit or incompatibility issues. The only tiny downside is some screen tearing when moving windows around. Thanks again for the advice and for insisting on me taking it

 

[Leborgne23]

Then the next "hard way" to work around this problem will be install Linux.

Boot to Linux, use QEMU to run Monterey in VM. And only PCIe passthrough the RX580 into the VM.

Which means, your client can boot 10.7 natively.

When want to use Monterey, boot to Linux, then start the Monterey VM. There will be a little bit performance hit, but should be very insignificant.

That will be my next option if the solution I settled for happens to not work properly (OSX LION running on Polaris with only framebuffer support). Thanks

 

[Leborgne23]

I think that your simplest, most direct solution would be to buy a second cMP 5,1. Your customer already has acquired the single most expensive component, namely the second GPU card. You're just asking a lot to make a single machine stretch that far back in compatibility, especially if you're using a pre-configured solution like OCLP.

Hi @flaubert.
Your advice would have been precious 18 months ago when even the slowest Polaris GPU was being traded for 250€. Now prices have dropped and I got the Polaris GPU for just 70€. My customer having 64GB of ram + upgraded CPU's + Flash storage it wouldn't have been that inexpensive to duplicate all that. Thanks

 

[Leborgne23]

Flash the cMP with EnableGop is a work around (IMO, you should do this whenever plan to install RX580 regardless has this issue or not). However, in this case, any software in 10.7 that need GPU power won't work. I doubt if your client can really accept that (If he only need some very basic function in 10.7. Then most likely he doesn't even need 10.7 now, but can move on. If he stuck with 10.7 because of some legacy software, then very likely he need a GPU that can provide acceleration in 10.7).

If you can install both GPU into the cMP. My suggestion is to learn how to disable a GPU via OpenCore. So that you can disable the 5770 in OpenCore (e.g. via SSDT).

Therefore, when your client boot the computer. It's defaulted to boot to OpenCore, which can then bridge boot to Monterey with 5770 disabled. In this case, the RX580 will do all the work.

When he need 10.7. He hold option to boot and select 10.7. Then the 5770 should work, and 10.7 should ignore the existence of RX580 (apart from that the RX580 will still draw quite a bit of power). With EnableGop, the RX580 can even still provide basic display function in 10.7.

I don't know how many monitors he use, but if only one, then he can connect both 5770 and RX580 to the same monitor. So that the same monitor can work with both cards in both OS.

Hi @h9826790 ! I did the first part and settled for the solution of using OSX LION with the Polaris GPU with only Framebuffer support. It runs surprisingly well. Thanks