As of late I have been looking into purchasing an SSD but have discovered my laptop (ASUS G51J-A1) only supports SATA II. I am considering getting the Samsung 830 SSD which has a SATA III interface.
I am pretty sure this is backward compatible with SATA II but is there any upgrade that would allow me to use SATA III to its fullest extent?
The SATA III drive is fully compatible with your SATA II interface and prices are no different for SSD's whether they are 3GB/s or 6GB/s. No internal upgrades are available to get the full speed but just the speed increase running it on your interface over the mechanical drive is worth the effort. The express card has external connections so not a good idea.