MP 1,1-5,1 Experience with MacVidCards Europe RX 6600 XT - no bootscreen

[h9826790]

Hi jsts,
I'm having the same problem. Bought a rx 6600 from macvidcards europe for a MacPro 5.1 with 24" Cinema Display and it does not show a bootscreen.
Firmware is on 144 everything worked with bootscreen with my old radeon 4870 and catalina, but it's not metal-able.
I also tried everything you did...but no success. I also used both cards at the same time, with two different displays. The cinema display connected to the old 4870 via miniDP and the rx6600 connected via HDMItoHDMI to the newer 24" Acer display. (I created an adapter for the two superdrives and used the power from there for the rx6600 - sure not to be done for daily business but should work just for booting experience).
It showed boot screen when both cards are installed but then stopped working when osx got loaded. Windows worked fine with both cards installed.
Whatever, not the solution for me as when you give some load on it...you can imagine it powers down. I wated a card that shows bootscreen natively as advertised on MVCeu as I also have a radeon VII running with no support and no boot screen (wanted to get rid of that).

When pulling the old card, nvram reset..adjusting the nvram again and starting with only the rx6600 installed...no EFI boot screen shows up.
Only the open core bootscreen works with the stick, but not natively.
Any news on this?

BE
Chris

I can understand why you prefer native bootscreen support. But did you ever try OpenCore? Its UEFI GOP boot picker works very well for Radeon VII actually.

 

[Derbyblu]

Ja, not the intention I was going for unlikely. I need a native boot screen as i have to be able to switch between different os.
So far..after long testing (16h up to now), it worked for me to get the bootscreen working.
NVram reset did not work. I disconnected it from power and also unplugged the mainboard battery for 15 min. Everything back in i started catalina and installed everything new, with both cards inside only working on the old 4870 with cinema connected. The rx6600 is connected hdmi to the Acer display and stucks/always showing the bootscreen with picking devices.
The other monitor runs normal os Catalina. I did exactly the instructions from macvidcards for installing Monterey (it only works with Monterey installer version 17.2.03 -> osx12.2.1).
I tried different ones all failed except this one.
After making the 2 bootable usb sticks with opencore and the other with micropatcher, i restarted the machine with opencore stick in it. Still having both cards in the Mac Pro. Bootscreen appeared and I have choosen the efi opencore like described in the instructions resulting in a black install screen with Apple logo but the progress bar keeps being unfilled..no progress at all.
I decided to only let the new card in, connected to the Acer via hdmi and rebooted. It worked having choosen the efi boot opencore again and then Monterey installer.
What should I say..it works finally.
It showed boot screen with device picker and it also started installation with progressbar filling up. 20 minutes to go.
Hopefully…

 

[Derbyblu]

I can understand why you prefer native bootscreen support. But did you ever try OpenCore? It's UEFI GOP boot picker works very well for Radeon VII actually.

I thought about it, really.
I have converted my Radeon VII with waterblock in my x86 amd Gaming station and it works like a charm.
For putting it pack to the Mac i would have to do the conversion back to normal which will result in the loudest graphics card i have ever heared. Fast but very loud.
So I preferred the described way above as i will use the Mac Pro mainly for Homeoffice use. So no Manor graphics hungry applications that will beat the rest out of him.
May the plan works now.
Jsts what version did you exactly install or try to install?
Br
Chris

 

[Derbyblu]

I thought about it, really.
I have converted my Radeon VII with waterblock in my x86 amd Gaming station and it works like a charm.
For putting it pack to the Mac i would have to do the conversion back to normal which will result in the loudest graphics card i have ever heared. Fast but very loud.
So I preferred the described way above as i will use the Mac Pro mainly for Homeoffice use. So no Manor graphics hungry applications that will beat the rest out of him.
May the plan works now.
Jsts what version did you exactly install or try to install?
Br
Chris

 

[Derbyblu]

Maybe I will sell the Radeon VII when this thing works. It has already been replaced with a rtx4080 that is also a lot quieter and also not so hot.
13 Minutes to go…

 

[Derbyblu]

Worked. Finally!!
Set the nvram settings, Mac Pro turned off.
Switched it back on without patcher stick and it works!
Shows boot screen, everything works fine!!

 

[Derbyblu]

Also cinema works fine.
Switching to windows is a little bit confusing as the screen stays black at boot and then suddenly the windows logo appears. But all works fine for me now.

Hope this helps anyone.
Just stay absolutely exactly to what’s described on macvidcards and maybe you do the nvramreset with battery.
This worked out for me and Monterey 12.2.1

@h9826790
You are absolutely right. Opencore would have been the solution then if this would not have been working for me. It is the only way you can use the Radeon VII in Mac Pro 5.1 originally.
Thx for that.

BR
Chris

 

[Dayo]

mvc's efi sets highest available resolution (aka mode 0).

I have noticed from RefindPlus logs from various users that while Mode 0 is usually that with the highest resolution indeed, it is not always the case. In such cases, whatever happens to be the highest mode number has the max resolution. As said though, Mode 0 is indeed usually that with the max rez.

 

[jsts]

Worked. Finally!!
Set the nvram settings, Mac Pro turned off.
Switched it back on without patcher stick and it works!
Shows boot screen, everything works fine!!

Sorry, but I still don't understand what exactly you did to make the white Bootscreen appear.

Did you try active converters? CAC-1335 and CAC-1336

No. I think it's useless. I have decided to sell the MacVidCards RX6600. I took the RX6600 out and put the Nvidia GTX 680 back in and am contemplating switching to the new Apple Silicon MacPro as soon as it becomes available.

I thank everyone for their support and help.

 

[startergo]

Sorry, but I still don't understand what exactly you did to make the white Bootscreen appear.




No. I think it's useless. I have decided to sell the MacVidCards RX6600. I took the RX6600 out and put the Nvidia GTX 680 back in and am contemplating switching to the new Apple Silicon MacPro as soon as it becomes available.

I thank everyone for their support and help.

Don’t sell it yet you can try the OC GOP boot screen patch to the original card vbios.