HP - P420i - Smart Array - High Profile - 1GB Cache -
689245-001 HP SMART ARRAY P420I 6GB/S MEZZANINE CONTROLLER CARD FOR HP PROLIANT SL4540 G8 - FOR I/O MODULE NO CACHE 8GB/S BANDWIDTH SUPPORTS SAS / SATA PCI-E 3.0 X8
FreeNAS only detecting 2 drives of Smart Array P420i | TrueNAS Community