Does XPS-17 (L702X)

Hi

Does anyone know what speed of SATA interface the Dell XPS-17 (L702X) have? Is it SATA2 (3Gb/s) or SATA3 (6Gb/s)?

I am looking into adding an SSD to it and am trying to work out how much performance boost I would get from it. I have found a few diagnostic programs that tell me that the disk that it shipped with is only SATA2 but that is sufficient for a spinning disk and doesn't mean that the interface can't handle more.

Thanks

Mog