Consider coreboot/libreboot? Not available for this Q45 chipset easily. Stick with HP’s final BIOS.
To update the BIOS of your HP Compaq 8000 Elite SFF PC, follow these steps: hp compaq 8000 elite sff pc bios update
. It’s the "v01.14" update, the holy grail for the 8000 Elite. You flash it to a small, low-capacity USB drive—the only kind the old machine will recognize. The Moment of Silence Consider coreboot/libreboot