from what i remember it's more so the controller used in the eSATA expresscard that allows booting from it. The Sil 3132 to my knowledge cannot be used to boot from. i have one and it just doesn't work with my MBP. I've heard the jmicron controller can boot from it, but don't quote me.
as far as those stating esata is slow or runs off USB, you either have no experience or have improper drivers installed.
despite Silicon image's lack in driver support, my 1TB WD black drive hooked up externally OUTPERFORMS my internal hitachi 320gb by a good margin.
as far as those stating esata is slow or runs off USB, you either have no experience or have improper drivers installed.
despite Silicon image's lack in driver support, my 1TB WD black drive hooked up externally OUTPERFORMS my internal hitachi 320gb by a good margin.