MP 1,1-5,1 Vega 56 in 5,1 cMP - No Startup Manager

[riven2000]

I just got a flashed RX Vega 56 on eBay for my 5,1 cMP, and now I can't boot to Startup Manager. Always goes straight to regular login. The description on eBay says: "These RX Vega 56 have been FLASHED for the Mac Pro tower, meaning they will display the grey boot screen at startup for startup disk selection . . . ." No mention is made of any mods needing to be done, including the Pixlas Mod I just started seeing while looking for a fix. Do I actually need this or another mod to use this card?!? Any help is GREATLY appreciated.

 

[h9826790]

Sounds like you just got a badly flashed card. Or that's a scam at the very beginning. However, something doesn't make any sense to me.

In order to show the start up manager, you have to hold Option key to boot. Assuming you are using a wired keybaord (or you known what's the correct time to press it for a wireless keyboard), then your cMP will either show you the Apple boot manager (if the card is working as ecpected), or hang with a black screen (if the card isn't flashed properly).

A badly flashed card will never ignore your keyboard input and send your cMP straight to the login screen.

So, at this moment, I cannot decide if your card is correctly flashed. But I more assume you haven't use it correctly.

Anyway, some more info for you. There is no need to buy flash card anymore.

If you just want boot picker. Install OpenCore will allow factory Vega56 to show you the boot picker.

If you want the native boot manager (hold option to boot), then you can flash you Mac with EnableGop.

So, don't worry if end up your card is badly flashed (of course, if that's expensive, I will ask for full refund). There are many ways to make it work.

 

[riven2000]

I'm using a Logitech USB keyboard, and with this card running, I've noticed the kb lighting goes out at the point I start holding Option (I start holding it right after the pitch black screen, just as the backlight starts up). I suppose it could be a kb issue. The Startup Mgr screen has been a bit hit and miss even without this new card.

Can I run OpenCore with Mojave? I had the impression it needed at least Catalina.

 

[h9826790]

Can I run OpenCore with Mojave? I had the impression it needed at least Catalina.

Of course, I initially use OpenCore to activate GPU HWAccel in Mojave on cMP. When I did that, Catalina not even exist.

Activate AMD hardware acceleration

I created a new "easy to install package" as per many requested (based on the official OpenCore). [The attached package updated to 1.0.0] For those who only need HWAccel, post #594 has everything you need. This new package mainly offer HWAccel + boot screen. Also, this package should work in...

forums.macrumors.com

 

[krakman]

There is a tiny bios switch on the card which switches between 2 bios modes.

Perhaps only one of those was flashed to show a boot screen.

I would try moving the switch and rebooting.

Maybe it could be a keyboard issue? Why don’t you buy a cheap Apple usb keyboard from eBay to eliminate that possibility. Try booting into recovery mode or safe mode using the Logitech keyboard. That way you can see if it actually functions properly at boot.

You can also put your old GPU back into the Mac Pro and see if the Logitech keyboard allows you to access the boot manager.

Finally if none of this works, return the card.

 

[Macschrauber]

A simple thing: OpenCore sets the background color to black, so maybe it's just a black screen instead of grey due to OC NVRAM settings.

Also one can force the boot picker if some other circumstances don't call it by if the keyboard don't is compatible with reading preboot firmware keys.

nvram manufacturing-enter-picker=true

when run from the Recovery or a booted installer or

with sudo before when NVRAM is not protected or on old systems like Mavericks.

 

[riven2000]

Thanks for all the help. I think it probably is a keyboard issue, as it's inconsistent between the new and old cards.

 

[riven2000]

Of course, I initially use OpenCore to activate GPU HWAccel in Mojave on cMP. When I did that, Catalina not even exist.

Activate AMD hardware acceleration

I created a new "easy to install package" as per many requested (based on the official OpenCore). [The attached package updated to 1.0.0] For those who only need HWAccel, post #594 has everything you need. This new package mainly offer HWAccel + boot screen. Also, this package should work in...

forums.macrumors.com

I've decided to return the Vega and have ordered a macvidcards.com Sapphire Pulse RX 580 8GB. Does HW accel need to be separately enabled for this one?

 

[prefuse07]

I've decided to return the Vega and have ordered a macvidcards.com Sapphire Pulse RX 580 8GB. Does HW accel need to be separately enabled for this one?

Why would you waste your money on that?

Seriously -- you could've just bought a NORMAL RX580 for cheap instead of paying the inflated MVC prices, and it works 100%.

As h9826790 previously mentioned to you -- you DO NOT NEED A FLASHED CARD.

 

[riven2000]

Actually I got it on eBay (I _WOULDN'T_ pay the mvc price, for the record). The seller said he originally got it from mvc. But you're right; an unflashed one probably would have been better. Thanks for the reminder. I'm still a little old school when it comes to video cards - "If it's a PC card in a Mac, it HAS to be flashed".

 

[h9826790]

Does HW accel need to be separately enabled for this one?

Yes, HWAccel on cMP is disabled by Apple, regardless the graphic card is flashed or not.

Actually I got it on eBay (I _WOULDN'T_ pay the mvc price, for the record). The seller said he originally got it from mvc. But you're right; an unflashed one probably would have been better. Thanks for the reminder. I'm still a little old school when it comes to video cards - "If it's a PC card in a Mac, it HAS to be flashed".

I won't recommend you go for any MVC flashed card nowadays. The problem isn't the flashing, but hardware modded. If we have no other way to get native boot screen. And MVC decided go to that way. Of course, pay him to do the job, and get whatever you can get.

But nowadays, just a tiny piece of non-invasive software (OpenCore) will allow a factory PC card to display UEFI GOP boot screen on the cMP. We really has no point to buy a used, and hardware modded, and flashed card with "higher than normal" price anymore.

Here is the demostration of what I can get from my un-flashed Radeon VII.

If this is what you want, then really no need to buy flashed card.

If you don't mind to flash your cMP with the EnableGop driver, then your cMP should have the identical boot screen function like you install a flashed card (I did that already, quite straight forward, and now I can hold Option key to boot my cMP with that un-flashed Radeon VII).

But TBH, for most normal users, simply use OpenCore is good enough (if don't want take the risk of firmware flashing).