Retina 5K, 27-inch, Late 2015 iMac17,1
Looking to upgrade the ssd blade from 250 GB to 1 or 2 TB and need direction as to where I can secure one. Wound this be a PCIe or a NVMe?
iMac 27″, macOS 14.5
OWC would usually be one of the go-to places for such drives. But on the page where I would expect to find any "blade" SSDs, there is a small note saying that their blade SSDs are not compatible with your Mac.
Other World Computing – OWC Solid State Drives For iMac 27-Inch (Late 2013 - 2019)
Crucial doesn't have any "blade" SSDs for your Mac – just 2.5" SATA notebook ones.
Crucial – Apple iMac (Retina 5K, 27-inch, Late 2015) iMac17,1 SSD Upgrades
If neither of these places has compatible "blade" SSD upgrades, I don't think that you going to have much luck elsewhere. Your Mac has old-style Thunderbolt ports, so Thunderbolt SSDs aren't going to be very practical.
Your best bet is to get an external USB SSD. Leave your OS and applications on the internal "blade" SSD – and offload some of your bulk data to the external SSD. You can get external 1 TB USB SSDs for ~$100 – and some might even be able to run at USB 3.1 Gen 2 speeds when attached to a USB-C port on your next Mac.
