I just ordered 1.0TB Mercury Extreme Pro 6G 2.5-inch 7mm SATA 6.0Gb/s Solid-State Drive from OWC to replace the failing 480 GB SSD.

Jon

macOS 11.7.10, iMac Retina 5K 27-inch, late 2014, 3.5 GHz Intel Core i5, 1 TB fusion drive, 16 GB RAM, Epson SureColor P600, Photoshop CC, Lightroom CC, MS Office 365