Sata connection on Vaio svs15.

Dear all,
I have a laptop Vaio svs15. I bought a ssd samsung 850 pro 120gb instead of HDD. But i found that, ssd runs with sata 2 speed. I have being read few theards, they said cause due to BIOS.
So, what version of Bios may o use in order to enable Sata 3? My laptop is Vaio svs15115fxb.