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dickiedunn

macrumors member
Original poster
Jun 7, 2019
60
1
Sorry for the newbie question, but I did do a search and didn't find an answer.

Thanks to everyone's help, I just upgraded my cMP 5,1 to High Sierra, Boot ROM Version:144.0.0.0.0, installed the RX580 and a new Samsung 970 Pro, which I formatted as APFS. My current boot drive is an AHCI SM951.

I used SuperSuper to clone my boot drive to the new 970 EVO. So far so good.

I'm used to holding down the option key when starting up and then selecting whichever boot drive is connected.

Is that no longer possible without the boot screen? Is there a workaround other than changing it in system preferences->Startup Disk?

I know the RX580 doesn't show a boot screen, but I though I would be able to workaround selecting a startup disk.

Thanks for any suggestions or workarounds.
 

dickiedunn

macrumors member
Original poster
Jun 7, 2019
60
1
Thanks, I know that is one option. I'm just worried if I select in preferences and the new drive doesn't work, if there is a way back.

So there is no way to use the old option key while starting up to select another drive?
 

tommy chen

macrumors 6502a
Oct 1, 2018
863
362
when is not work there is a problem with the system on the NVMe,
or with your PCIe adapter

and it will be the same problem if you have a bootscreen with the option-key methode
 

h9826790

macrumors P6
Apr 3, 2014
15,476
7,745
Hong Kong
Thanks, I know that is one option. I'm just worried if I select in preferences and the new drive doesn't work, if there is a way back.

So there is no way to use the old option key while starting up to select another drive?

If that happen, then perform a NVRAM reset will always bring you back to the first located macOS boot drive. No need to worry about using that system preference startup disc selection.
 

dickiedunn

macrumors member
Original poster
Jun 7, 2019
60
1
So just to confirm, on a healthy system with RX580 it is impossible to hold the option key down when restarting and select a boot drive from the screen as there is no boot screen? Do I have that right?
 

tsialex

macrumors G4
Jun 13, 2016
10,654
11,180
So just to confirm, on a healthy system with RX580 it is impossible to hold the option key down when restarting and select a boot drive from the screen as there is no boot screen? Do I have that right?
Yes, you are right - no boot picker. Only GPUs with pre-boot configuration support work before the drivers are loaded by macOS.
 

DearthnVader

macrumors 68000
Dec 17, 2015
1,517
6,083
Red Springs, NC
You can use the command line "bless" command with --nextonly and it will only change your startup disk for the next boot only, then revert to the startup disk in nvram.

That way you can test your new install without changing from the working install.
Code:
 man bless

:
 

ActionableMango

macrumors G3
Sep 21, 2010
9,610
6,891
You can use the command line "bless" command with --nextonly and it will only change your startup disk for the next boot only, then revert to the startup disk in nvram.

That way you can test your new install without changing from the working install.
Code:
 man bless

:

Bless still works? Years ago I seem to recall having problems using it and when I looked it up, it had been deprecated even back then.
 

Soba

macrumors 6502
May 28, 2003
401
582
Rochester, NY
I used SuperSuper to clone my boot drive to the new 970 EVO. So far so good.

A small suggestion: For a boot drive like this, you might want to use Carbon Copy Cloner. This will also bring over your Recovery partition, which can be very handy. I love SuperDuper, but it does not handle Recovery partitions.

Others have answered your main question, but I'll also add that it's a good idea to keep your original graphics card just in case of a problem. It never hurts to have a backup option.
 

h9826790

macrumors P6
Apr 3, 2014
15,476
7,745
Hong Kong
Yes, bless still works, I use it all the time, but it can be a steep learning curve.

Tho you have to disable SIP, so that's not so easy without boot screens.

Disable SIP should be fairly straight forward. Recovery partition has it’s own GPU driver, simply hold Command R can boot to recovery partition.
[automerge]1575946888[/automerge]
Bless still works? Years ago I seem to recall having problems using it and when I looked it up, it had been deprecated even back then.

It still works, this is how we bless the boot partition in the OpenCore discussion.
 

deconstruct60

macrumors G4
Mar 10, 2009
10,557
2,555
Thanks, I know that is one option. I'm just worried if I select in preferences and the new drive doesn't work, if there is a way back.

So there is no way to use the old option key while starting up to select another drive?

If there is only one bootable drive to pick from the system's doesn't have a choice. ( can remove something that doesn't work. )
 

dickiedunn

macrumors member
Original poster
Jun 7, 2019
60
1
A small suggestion: For a boot drive like this, you might want to use Carbon Copy Cloner. This will also bring over your Recovery partition, which can be very handy. I love SuperDuper, but it does not handle Recovery partitions.

Others have answered your main question, but I'll also add that it's a good idea to keep your original graphics card just in case of a problem. It never hurts to have a backup option.

Thanks for the suggestions! Are you sure though that SuperDuper doesn’t do this? On their website they say the latest version has “APFS recovery volume support”. Is that not the same thing? My current SM951 boot drive is formatted as an APFS drive, and I used SuperDuper to clone it over to the new NVME 970 Evo.

I will definitely be hanging on to my original graphics card just in case.
 

Soba

macrumors 6502
May 28, 2003
401
582
Rochester, NY
Thanks for the suggestions! Are you sure though that SuperDuper doesn’t do this? On their website they say the latest version has “APFS recovery volume support”. Is that not the same thing? My current SM951 boot drive is formatted as an APFS drive, and I used SuperDuper to clone it over to the new NVME 970 Evo.

My apologies! It looks like this is a brand new feature in v3.3 and I will be trying it out, myself.

Edit: Apparently this feature was introduced in SuperDuper! v3.0 in 2017. Oddly, it was never mentioned in the release notes and is only found on the blog.
 
Last edited:

dickiedunn

macrumors member
Original poster
Jun 7, 2019
60
1
Thanks Alex. Also, just to make sure I have this correct before I pull the trigger. I've cloned my AHCI Boot volume over to my new NVME blade. After I run the Mojave installer to update the new NVME blade to Mojave, if for some reason Mojave doesn't work out, I can always go back and reboot off of my older AHCI boot drive that is on High Sierra? In other words, can I go back to High Sierra if something goes wrong with the NVME Mojave update?
 

tsialex

macrumors G4
Jun 13, 2016
10,654
11,180
Thanks Alex. Also, just to make sure I have this correct before I pull the trigger. I've cloned my AHCI Boot volume over to my new NVME blade. After I run the Mojave installer to update the new NVME blade to Mojave, if for some reason Mojave doesn't work out, I can always go back and reboot off of my older AHCI boot drive that is on High Sierra? In other words, can I go back to High Sierra if something goes wrong with the NVME Mojave update?
Since you are using a GPU without pre-boot configuration support, you can always remove the NVME blade and reset the NVRAM 3 times in a row, your Mac Pro will then boot from the AHCI blade.
 

dickiedunn

macrumors member
Original poster
Jun 7, 2019
60
1
Interesting, thanks. You really are a wealth of knowledge. Thank you for all you do on this forum.
 
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