I have a mid-2012 5,1 6-core 3.33 ghz machine that I have been running an OWC Mercury Accelsior E2 PCIe SSD (960gb) for a couple of years now. I originally had it as my boot drive and it worked just fine through High Sierra. However, on Mojave it "ejects" or is undetected intermittently. I had an alternate spinning HD with HS that the machine would boot to whenever the SSD was not detected. I reset both NVRAM and PRAM and it would usually recognize the SSD again. Alas, on a reboot this process would periodically have to be repeated. When I power on the machine with the case open I can see a red light on the Mercury SSD come on. When it is detected, the light will eventually begin to flash. When it is not detected, the light stays solid but nothing else happens.
In frustration I recently replaced the backup boot spinner drive with an OWC Mercury Extreme Pro 6G SSD, 2.5" Drive and installed Mojave on it and it is now my primary boot drive. The OWC Mercury PCIe SSD is still installed, but it "ejects" all the time. Even get multiple warning messages on my screen when waking from sleep that the "drive was not ejected properly." It may or may not show up again over the course of several wake-from-sleeps, but when it does appear it functions just fine.
I'm on the latest version of Mojave as of today, 10.14.3, and boot rom is 140.0.0.0.
Bay 1: OWC Mercury Extreme ssd
Bay 2: Spinner (bootcamp) another forgotten feature!
Bays 3 and 4: Two spinners in software Raid 1.
PCI Slot 1: Radeon RX 580
PCI Slot 2: empty
PCI Slot 3: OWC Mercury Accelsior E2 960 gb
PCI Slot 4: USB 3.1 expansion card.
I do have all the latest OWC Mercury E2 drivers installed so I am just throwing this out to all the wizards to see if anyone has any ideas.
Note that I do recognize that it is maybe just a symptom of the drive going bad. But I sent it back to OWC in early 2018 and they confirmed it was working just fine.
In frustration I recently replaced the backup boot spinner drive with an OWC Mercury Extreme Pro 6G SSD, 2.5" Drive and installed Mojave on it and it is now my primary boot drive. The OWC Mercury PCIe SSD is still installed, but it "ejects" all the time. Even get multiple warning messages on my screen when waking from sleep that the "drive was not ejected properly." It may or may not show up again over the course of several wake-from-sleeps, but when it does appear it functions just fine.
I'm on the latest version of Mojave as of today, 10.14.3, and boot rom is 140.0.0.0.
Bay 1: OWC Mercury Extreme ssd
Bay 2: Spinner (bootcamp) another forgotten feature!
Bays 3 and 4: Two spinners in software Raid 1.
PCI Slot 1: Radeon RX 580
PCI Slot 2: empty
PCI Slot 3: OWC Mercury Accelsior E2 960 gb
PCI Slot 4: USB 3.1 expansion card.
I do have all the latest OWC Mercury E2 drivers installed so I am just throwing this out to all the wizards to see if anyone has any ideas.
Note that I do recognize that it is maybe just a symptom of the drive going bad. But I sent it back to OWC in early 2018 and they confirmed it was working just fine.
