T420/520 BIOS

[mdclow]

Does the BIOS for the T420/520 allow for booting from the eSATA port?

[hunterman223]

I can't find anything with google, but I would assume so. Any laptop I have come across with eSATA had the ability to boot from it, as eSATA is basically a SATA port. If you really need to know ahead of time, call up lenovo and ask them.

[mdclow]

Your answer is sufficient for me at this time as the answer is not a deal breaker when I get ready to replace my T60 sometime in early 2012.

[blackomegax]

ill let you know later today when i try to do just that. 2012 will bring new thinkpads anyway.

[blackomegax]

eSATA is bootable. but flakey.

my esata WD sometimes does not get seen by bios. when it does, it boots.
the same device on usb will boot.

/edit from flat out saying it doesnt boot.

[Colonel O'Neill]

Sometimes the BIOS doesn't recognize the drive at cold boot; hitting Ctrl+Alt+Delete right after POST to trigger a restart gets it to see it 100% of the time.

[blackomegax]

yeah, i decided to take a crack at this issue a bit more, it had a lot to do with drive spin up time (the external device houses two drives in RAID1, which it cannot spin up simultaneously due to power constraints of its small power brick.) A single drive or 2.5" esata device should have less issue. And a simple reboot should pick it up.