I know that you have sunk cost in the components for the internal swap, but I would see what the external drive would do for you for now. The thing is, the external drive will give you read/write speeds around 1400 MB/s, some 5x the fusion drive.

For another $79 to OWC, you could get yourself an Envoy Express enclosure to do this. I would want to have the NVMe setup and know that it boots before I installed it. Since you have separated a fusion drive, you do not have the option to use the former internal drives in an enclosure to boot the machine if the USB install goes awry. At a minimum, you need a bootable USB installer. Which, if true for your iMac, means that you are not good to go. I believe that OWC is effectively telling you that you cannot use internet recovery to install MacOS on the NVMe (this is known for other Macs like the trash can Mac Pro 6,1). I just plugged in the external drive with the installer and boom.ĭisclaimer: I chose to go the route of an external TB3 boot drive for my 2017 iMac rather than what you are proposing. That actually ended up as a crucial part, because internet recovery wouldn't work. Thanks to u/Man_in_High_Castle for the tip about the bootable external drive. Getting 2000MB/s write and 3000MB/s read. Installed macOS Monterey on the blade SSD. I went and did the upgrade with no problem what so ever. I just want to be sure that I can remove the current discs, put in the new ones, and THEN install Mac OS by Cmd-Opt-R booting?Īm I forgetting something or am I good to go? Without the update, the host computer will not recognize the drive. The Mac OS versions include a EFI update. The OWC SSD came with an 'important notice' that says MacOS has to be installed on the host computer BEFORE installing the drive. My plan is to follow the iFixit guide to replace the drives. I don't want to migrate the system, I want to start fresh. I am going to upgrade my Fusion drive 2017 27 inch iMac.

Best ssd for imac 2017