Is it possible to boot from an external eSata drive on a MacBook Pro?

Question

Using an ExpressCard/34 eSata card in a MacBook Pro, is it possible to boot from an external eSata drive, which has an installation of Mac OS X 10.6 on it?

The card in question is this one, which has a SiliconImage SiI3132 chipset.

Answer 1

According to this account you can.

Yes, you can boot Mac OS 10.6.4 via eSATA

Answer 2

Not all eSATA cards work. The OWC card (single SATA port) did, the dual port cards did not. Further, I was unable to boot from a powered docking station but was able to boot from a quad interface AC powered drive. I have not tried OWC's bus powered eSATA drives because they draw additional power through the Firewire 800 port.

So the bottom line is yes, but only some combinations work. It is also possible to boot OS X 10.7 by this approach as well.