The new 4TB NVMe SSD will be put in the same port the old NVMe SSD was. I'm simply taking out the 1TB HP NVMe and putting in a faster 4TB one. It will no longer be fused with the 2TB Samsung QVO currently in the SATA slot, so I guess that could make it slower than fusing them, I don't know.
That is the ideal configuration and what I meant to imply, but obviously did not. Fusing the drives is NOT recommended -- as I said, macOS no longer supports Fusion drives.
Ok, thank you, that makes sense.
The place I originally bought the iMac from has offered to do the work for me at a great price, but the downside is due to shipping times it would give me about a week without it. If I can't find a local tech to do the work after calling around tomorrow I'll have to go that route.
