Can I insert a SATA II (3Gb/s) drive into a SATA 6Gb/s slot?
Solution 1:
SATA is supposed to be both backwards and forwards compatible, so anything that actually meets spec should work on anything else. You can use SATA2 drives on SATA3 interfaces, and you can use SATA3 drives on SATA2 interfaces. This is no different from when SATA2 first came out with SATA interfaces, except that more devices meet spec properly so you shouldn't have to set jumpers or anything like that - it should Just Work™. (Note, of course, that you'll always run at the speed of the slowest link in the chain.)