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A1419 mid 2017 iMac 27” Retina 5k 3.4 ghz 1tb Fusion Drive I have the 1tb fusion drive with the tiny blade ssd and will be replacing both drives with a 2tb sata ssd and an Apple 128gb blade ssd pulled from another computer. Since the fusion drive is actually 2 separate units, I am a little confused as to how to go about cloning the drive and installing OSX on the new blade ssd. Will cloning the fusion drive to the 2tb sata ssd produce a copy of both drives onto the sata that can boot the computer once installed? How can I load OSX on the new 128gb blade ssd? Once OSX is on the new 128 gb blade ssd and is being used to boot the computer and everything, what happens to the copy of OSX that was on the 2tb sata drive that was cloned? I do a lot of audio and video editing, Logic Pro and Final Cut, what is the best way to take advantage of the new higher capacity blade ssd? Should only OSX go on the blade? Should I combine the two drives together to make another fusion drive? Sorry for so many questions. I am totally competent in the teardown and installing of components. I have the right tools and access to a clean room at work (and permission to use it), and anti static mats, and experience tearing down iMacs. I just am unsure of how to go about the software side of things. Thanks for reading. I’ve gotten a lot of help from reading the ifixit question and answers. Update (08/04/2019) Thanks again Dan. I successfully upgraded my iMac and everything is working smoothly with no problems.
You don’t clone! You first need to break the Fusion Drive set following this How to split up a Fusion Drive Remember the SSD is not seen directly its nearly a cache drive to the HDD. Given what you are planing on using I would recommend you leave your new drives independent. I would go with a larger blade SSD if you can. 256 or better yet a 512 GB. That way you’ll have plenty of space for your OS, Apps and the rest of the drive is left empty! This allows the OS & apps space for caching, paging & scratch space. Your data will be on the HDD. If you can go with a high RPM hybrid SSHD 3.5” SATA drive so you gain some additional performance.
