Sata 2 Sata 3 Compatible
Jack Munzel is correct, they are backwards compatible. As for why, well, it was designed that way. In order to allow people to continue using their old hardware, the designers of SATA III decided to use the same port. sata 3 HDDs wont work in sata2 normally, there may be jumpers that can be set on the HDD to lower its speed to 3Gbps. im getting the HDD in a parts combo on newegg, i just needed to know if they would be compatible.