Do hard drives need a GUID partition table (GPT) to boot in UEFI mode

biosbootdvdhard driveuefi

Is EFI booting something hardware specific? I have a desktop motherboard with a UEFI Bios, but I can only boot from USB drives in "UEFI" mode. Both the DVD drive and the HDD's (a RAID 0 array) boot only on legacy mode. Do the HDDs need to have a GPT partition table in order for them to boot in UEFI mode?

Best Answer

(U)EFI-based systems, by specification, can only boot from GPT-style disks. The traditional BIOS can boot from MBR-style disks, and in some cases (depends on the manufacturer), they can also boot from GPT. However, as per the UEFI specification, the disk should have a GPT partition table.

This MSDN article describes it well:

Systems that support UEFI require that boot partition must reside on a GPT disk. Other hard disks can be either MBR or GPT.