How do my MBR disks work with my UEFI motherboard?

[pickandwhammy]

I have an ASUS M5A97, Windows 8.1 on a 64 GB SSD (MBR), a partitioned 1 TB HDD (MBR), and two external HDDs (MBR). However, I read here that newer PCs with UEFI systems require GPT. I'm sure I am misunderstanding some concepts - would appreciate it if they would be pointed out. TIA!

 

[mouse24]

GPT is only required if the system has a disk >2tb. Even then you can partition off part of the drive so you're left with an MBR partition of 2tb + 1tb.

 

[cirdecus]

Your PC does have UEFI, so if your hard drives are configured using MBR, then they obviously work just fine. GPT is for larger drives. However, i wouldn't use MBR on anything other than a boot drive honestly.

 

[Someone Somewhere]

Windows is weird. If you're booting in Legacy mode, your boot drive must be MBR. If you're booting in UEFI mode, your boot drive must be GPT. No other OS that I know of does this.

All UEFI boards also support legacy booting.

You can have any mismatch of MBR/GPT drives you like in a system, so long as the boot drive matches the above conditions.

(Note: Macs are weird. Not sure about them)

 

[pickandwhammy]

Your PC does have UEFI, so if your hard drives are configured using MBR, then they obviously work just fine. GPT is for larger drives. However, i wouldn't use MBR on anything other than a boot drive honestly.

Windows is weird. If you're booting in Legacy mode, your boot drive must be MBR. If you're booting in UEFI mode, your boot drive must be GPT. No other OS that I know of does this.

All UEFI boards also support legacy booting.

You can have any mismatch of MBR/GPT drives you like in a system, so long as the boot drive matches the above conditions.

(Note: Macs are weird. Not sure about them)

Ah, so it's an OS issue, not defined in the standard! Is "legacy boot" a UEFI option or an OS-level (Windows) option? I'd tried to mess around with EFI/Ubuntu-64 on VirtualBox to get a better idea of this, but it doesn't seem to work on the hypervisor (it's supposedly still "experimental").
As for using GPT on non-boot drives, apparently I can't seamlessly migrate if the drives are partitioned - if there's a way, I'm more than willing to try it out!
Thanks for the responses!

 

[Someone Somewhere]

Legacy boot is in the UEFI - it pretends to be an old BIOS.