Chosen Solution
i have purchased FLEANE FM13A 1TB PCIE 3,0X4 NVME and OWC 2TB 6G SSD, and I installed both on my IMAC late 2013, however, I noticed that the OWC is mounted but as storage only (like an external storage drive) while the PCIE contains all the IMAC operating system that I got from the migration process after installing it. My intention was to use the 2TB OWC storage to boost my IMAC storage and to have the PCIE increase the boot speed of the apps. please advise how can I fix it and if can I have both at the same time.
It sounds to me like you’re trying to use these drives like a fusion drive. So you’ll get the speed boost of the PCIe drive, but the storage capacity of the larger SATA SSD. But what you’re seeing now is two separate drives. One with the operating system and all your migrated data, and one with nothing, but you can move files to it like you would with an external drive. You’ll need to combine them to make them into the fusion drive you’re looking for. I don’t know that the performance boosts from the PCIe drive will be noticable on this model with an SSD in both slots since even PCIe is not much faster than SATA. This would be a more logical method if you were using an HDD. But regardless. You’ll need to follow this guide from Apple to combine the drives the way you want. Keep in mind it will erase all the data on both drives.
@flannelist & @sam1968 - While the file system would be flat, the storage space is only the size of the SATA drive not the total of the two drives! So in this case 2TB! Not the physical 2+1=3TB This is both a space ($$) waste and really no performance improvement. From a performance perspective: Hits you in both the limits of the PCIe/NVMe interface this series has PCI 2.0 and the number of lanes x2 while faster than the SATA III (6.0 Gbps) interface the OS’s overhead for Fusion Drive services mostly wastes that gain! This drive is running in compatibility mode if it’s working at all. A cheaper PCIe 2.0 x2 would have been a better choice and I would have used a 256GB drive for the Fusion Drive cache drive as being the better fit. I’m still not a lover of using M.2 drives more so in iMac’s given the work required to get to it. These drive/adapter setups are not that reliable Vs either using a real Apple or OWC SSD. Now the better solution is to leave these as independent drives, using the Blade drive as the boot drive as well as the drive which hosts the applications as the app will be constantly need access (caching & paging) and some need scratch space which is best to leave on the blade as well. The OS also gains performance being on the Blade drive here we have it’s Caching and Virtual RAM it uses. Then use the slower SATA interface drive for the bought media (music and vids) as well as your own creative work and most everything else. Now to get into making things appear flat only needs the use of Aliases! Here placing them within the users folder within the blade drive or what I had done is just copy over the users home folder to second drive and then place the Alias within the Blade drive there’s a few tweaking needed to make this work which is a bit more involved within APFS.