Interesting! I ran the exact same setup on my Macbook Pro 2012. I had a 1TB HDD that came with it. I replaced my CD rom drive with 870 EVO 1TB SSD. I turned the EVO into my boot drive and used the internal HDD as a data drive. I ran W10 with fusion mainly for Quicken. That MB Pro 2012 was the best machine ever. I was afraid it was going to just up and die on me. I went with Macbook Air M1 and gave the 2012 to my Granddaughter. Still running and pretty fast, albeit a little warm.