Two boot cycle with 970EVO

skizzo

macrumors regular
Original poster
Apr 11, 2018
238
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I think I have seen at least one other member post about this, being @crjackson2134 (sorry if I got the wrong member or this issue is completely different)

I have noticed that I occasionally got a two cycle boot when selecting my 970EVO NVMe SSD running 10.13.6 with HFS+ formatting. By this I mean the first boot looks totally fine except when it should go to the desktop it just restarts. On this 2nd boot attempt it does make it to the desktop. Here are some facts

  • This has occurred several times now when selecting different disks in a particular fashion/method (detailed below).
  • I NEVER have this happen when using an EFI GPU and using the ALT boot selector at start up. No matter if I am changing from a macOS disk or a Windows disk, if I use the boot selector this does not occur
  • It ALWAYS occurs every time I select a different disk than the 970EVO from the "Startup Disk" app in System Preferences, and then also use the Startup Disk app in macOS or the boot camp control panel in Windows to select back to the 970EVO it ALWAYS does this dual boot startup.
  • HOWEVER, if I use the Startup Disk selector to go to a different disk other than the 970EVO, if I use the boot selector to get back to the 970EVO from either macOS or Windows this dual boot does not occur
  • Using a non EFI GPU is possible too, but I have to use Boot Manager to boot to different disks and the app automatically boots back to the 970EVO on the next boot cycle. With the lack of the boot selector feature on an non EFI GPU I am forced to use Boot Manager, since the built in Startup Disk selector will create the dual boot everytime whether using a EFI GPU or non EFI GPU

So I am particularly curious if anyone else in the community is experiencing similar events?
Anyone else have a better work around method or resolved the issue?


PS. I am on the 140 firmware which allows NVMe booting
 

handheldgames

macrumors 68000
Apr 4, 2009
1,706
930
Pacific NW, USA
I think I have seen at least one other member post about this, being @crjackson2134 (sorry if I got the wrong member or this issue is completely different)

I have noticed that I occasionally got a two cycle boot when selecting my 970EVO NVMe SSD running 10.13.6 with HFS+ formatting. By this I mean the first boot looks totally fine except when it should go to the desktop it just restarts. On this 2nd boot attempt it does make it to the desktop. Here are some facts

  • This has occurred several times now when selecting different disks in a particular fashion/method (detailed below).
  • I NEVER have this happen when using an EFI GPU and using the ALT boot selector at start up. No matter if I am changing from a macOS disk or a Windows disk, if I use the boot selector this does not occur
  • It ALWAYS occurs every time I select a different disk than the 970EVO from the "Startup Disk" app in System Preferences, and then also use the Startup Disk app in macOS or the boot camp control panel in Windows to select back to the 970EVO it ALWAYS does this dual boot startup.
  • HOWEVER, if I use the Startup Disk selector to go to a different disk other than the 970EVO, if I use the boot selector to get back to the 970EVO from either macOS or Windows this dual boot does not occur
  • Using a non EFI GPU is possible too, but I have to use Boot Manager to boot to different disks and the app automatically boots back to the 970EVO on the next boot cycle. With the lack of the boot selector feature on an non EFI GPU I am forced to use Boot Manager, since the built in Startup Disk selector will create the dual boot everytime whether using a EFI GPU or non EFI GPU

So I am particularly curious if anyone else in the community is experiencing similar events?
Anyone else have a better work around method or resolved the issue?


PS. I am on the 140 firmware which allows NVMe booting
I also get the dreaded double boot when I switch startup disk from a SATA II attached apfs SSD with Mojave to a PCIe 3.0 970 pro nvme apfs with mojave.
 

skizzo

macrumors regular
Original poster
Apr 11, 2018
238
68
I also get the dreaded double boot when I switch startup disk from a SATA II attached apfs SSD with Mojave to a PCIe 3.0 970 pro nvme apfs with mojave.
Seeing you have RX470, RX480, and an EFI capable 7950 you're basically in the same exact boat as me.
I would recommend using Boot Manager to avoid dual boots on the cMPs with the RX470 and RX480. Your cMP with the 7950 will be perhaps easier to manage by having access to the Boot Selector at startup (though not sure if this issue occurs on that systems SSD being it's AHCI not NVMe. Could you comment that this issue does NOT occur on the cMP with the Apple SSUAX AHCI PCIe 512GB? This could suggest something about NVMe or non-apple PCIe SSD if the issue doesn't happen on an Apple PCIe AHCI SSD).

I don't have a clue if this two boot cycle is actually harming anything other than our patience waiting for our computers to start up lol. so far seems more like an inconvenience rather than indicating there is some failing hardware, incompatible software, or something similar

I also wanted to show this has nothing to do with the RX580 or other vendors varients. A few posts have put suspicion on a particular combo with the NVMe SSD and a Sapphire Pulse RX580 8GB. This happens when I have other PCIe cards installed or no other PCIe cards besides the GPU and NVMe SSD. It happens with other GPUs such as the GT120 and HD5770, and from your comment we can also add RX470 and RX480 to that list. So seems completely unrelated to a particular hardware configuration
 

handheldgames

macrumors 68000
Apr 4, 2009
1,706
930
Pacific NW, USA
Seeing you have RX470, RX480, and an EFI capable 7950 you're basically in the same exact boat as me.
I would recommend using Boot Manager to avoid dual boots on the cMPs with the RX470 and RX480. Your cMP with the 7950 will be perhaps easier to manage by having access to the Boot Selector at startup (though not sure if this issue occurs on that systems SSD being it's AHCI not NVMe. Could you comment that this issue does NOT occur on the cMP with the Apple SSUAX AHCI PCIe 512GB? This could suggest something about NVMe or non-apple PCIe SSD if the issue doesn't happen on an Apple PCIe AHCI SSD).

I don't have a clue if this two boot cycle is actually harming anything other than our patience waiting for our computers to start up lol. so far seems more like an inconvenience rather than indicating there is some failing hardware, incompatible software, or something similar

I also wanted to show this has nothing to do with the RX580 or other vendors varients. A few posts have put suspicion on a particular combo with the NVMe SSD and a Sapphire Pulse RX580 8GB. This happens when I have other PCIe cards installed or no other PCIe cards besides the GPU and NVMe SSD. It happens with other GPUs such as the GT120 and HD5770, and from your comment we can also add RX470 and RX480 to that list. So seems completely unrelated to a particular hardware configuration
While I've heard of boot issues with the Sapphire Pulse RX580 and the 970 Pro, I haven't had any conflicts with the RX480 & RX470 and the 970 Pro.

Aside from that conflict, the dual boot issue is an artifact of booting between NVMe and SATA or NVME and AHCI SATA Express. It's been around since we started injecting NVMe boot support into the cMP firmware. The system chimes and starts to boot. At the point the SATA bus is initialized and the drives are polled, the system reboots, going through the chime and boot sequence a second time.
 
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skizzo

macrumors regular
Original poster
Apr 11, 2018
238
68
thanks for that info! that is what I was wondering. it's a known issue. I never did any injecting hacks to get NVMe booting so was not aware.
 
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