Amazon.com: HP Z420 Workstation- 4 Core E-1620 3.6Ghz up to 3.8GHz CPU- 32GB RAM- 1TB SSD + 4TB Hard Drive with 3 YR WNTY- Nvidia 4000 2GB DDRR5 Graphics Card- Windows 10 Pro - USB 3.0 : Electronics
Installing NVME Boot drive on HP Z400 with legacy BIOS [950 PRO SSD] - YouTube
A bootable NVMe ssd on Z420: SAMSUNG PM963 - HP Support Community - 7151420
Solved: Booting to NVMe ON Z820 HP AND Z600 - HP Support Community - 6953042