I have an Alienware M14x-R1 and had an Arch Linux System installed on its 750Gb HDD, everything working fine, GPT-partitions (on BIOS, not EFI) and GRUB bootloader.
Then I bought a new Corsair SSD, replaced my old HDD and installed Windows 7 on it for work purposes. I also bought an external HDD casing from SilverStone (Raven RVS02) thats USB 3.0 and I can mount my linux GPT Partitions just fine.
But when I try to boot the ArchLinux system from the USB I get no options on F12 (Chose Boot Disk) for it.
I found this site that someone says he could use an OpenSuSe 12 but only on the USB 2.0 port.
So my questuin is, Is there a way I can use Arch Linux (or any other distro, I don't think the distro matters that much) on a GPT-Partitioned external HDD booting from USB 3.0 on a BIOS system?