X4 series Ethernet adapters support UEFI. It is enabled in the delivered factory configuration.
Note: To change whether UEFI is enabled, you must
program new configuration settings into the adapter.
PXE Booting
X4 series Ethernet adapters do not support legacy BIOS PXE booting.
PXE over UEFI is supported. This requires a host that uses UEFI for booting and where its UEFI implementation implements PXE. The host can then use the UEFI functions of the X4 series Ethernet adapter to run PXE over that adapter.