I think you have ddr3 8gb...
most to all bios has the setup for ram clock. The computer default to pc1333 even you has pc1600 for safe boot up. For laptop, most of them will not let you change the ram clock, I don't know why because I have Dell laptop.
I have G.Skill ddr3-1600 pc3-1200 16GB(2x8) make sure that you installed in the socket A1 and B1, A2 and B2
But my desktop MOBO, AsRock 990FX extreme3 has the default to pc1333; I change to pc1600. The speed improve a little bit, but not significant enough.
Finally, I manually change the Tr 10-10-10-30T, that is the actual clock for these ram and it run great, too fast.
I installed old ram pc1300 has 9-9-9-24, and force it overclock it work too. So far, it not crash yet.