Getting rid of the Fusion Drive for a WD SN770 NVMe SSD Blade
I want to upgrade a 27” 5k 2019 iMac that has a fusion drive in it.
With the Big Sur update, it became horribly slow. The fusion drive was probably a poor choice from the beginning. It’s my mom’s mac and she was scared she wouldn’t have enough storage with a 250GB SSD, even though I explained to her that internal SSD + external thunderbolt drives were the best choice.
So I guess I have two options:
A/ Removing both the fusion drive SSD and the drive and putting a Sata 2.5” SSD in place of the original HDD as the main internal drive. I think 2019 iMacs have 2,5 format HDDs, so I suppose putting a 2,5 SSD wouldn’t require any adapter. It’s the choice I like the least as NVMe M2 SSD has dropped in price and are faster than SATA SSDs.
B/ Removing both the fusion drive SSD and replacing it with an NVMe M2 SSD (and also removing temporarily or permanently the HDD as it is linked in a fusion drive setup, and needs at least to be “unlinked”. I think I might just dump it all together for convenience.”
I like this option better, but I have several questions:
1/ Regarding data migration, I read here that since the system partition is APFS, it’s not possible anymore to just clone the whole partition with Carbon Copy Clone to the new NVMe M2 SDD plugged in externally in some kind of enclosure. This puzzles me because CCC states that it can work with APFS and I know for a fact that until Mojave at least, it did a good job cloning not only the data but a recovery partition as well. I’m quite reluctant to use the data migration tool provided by Apple, which relies on Time machine if I’m not mistaken because I had issues with it in the past…
@danj, you seem to know a lot about this, can you please confirm it to be that using CCC for this isn't possible anymore, given that the version of Mac OS used here is Big Sur?
2/ Regarding the hardware, I saw videos of guys doing basically this, but it seems that an adapter is needed. Which ones are known to be working for this upgrade?
3/ Also, regarding the M.2 SSD that I would use for this, I was thinking about a Western Digital SN770 NVMe because I read on a Hackintosh forum that these were always compatible with recent Macs, as WD is now the main company that Apple relies for its production concerning SSDs. Is there maybe a more natural choice for this upgrade?
Thank you in advance for your help :)