[NAME] You did not indicate whether or not the 870 EVO was the boot drive in the x51. If the 870 EVO was a boot drive, when you install it in the new computer you will have to boot using the F12 Boot Menu and then select to boot from the NVMe SSD (assuming the NVMe SSD is the new boot drive). As long as the 870 DVO is installed in the new computer you will need to use the F12 Boot Menu to boot until you reinitialize the 870 EVO to use as a "D" drive.
I have a 2012 x51 that has reached the end of life. In it I have a Samsung 870 EVO 2TB 2.5 Inch SATA III Internal SSD. I'm about to replace that x51 with one of the new loaded down XPS machines that will have the 2 TB, M.2, PCIe NVMe, SSD option and I was wondering for simplicity sake if I can plug that 870 EVO into the new XPS to transfer the files I want to keep, then reformat it and use it in the XPS as a "D" drive. TIA.
Moving Data to New Computer