enamak :
Did with stock for 1 hour went fine (1 hour is small time but since i got errors at 5 mins (at 1600MHz) now must bê fine.
How can i overclock to 1600 safelly? Or should i use cl8 1333
well, the thing to remember about OC'ing, is to make sure it's stable

You start OC'ing low, and work up in increments, testing along the way to ensure it's stable. It's time consuming. It can be worth the effort. I have a an older system OC'ed and the benefit is huge. But to just OC ram, isn't going to be much benefit to you at all.
Ram is funny, you can have fast speeds, but higher latencies, or slower speeds with small latencies. If your CPU is running at 1333 or equivalent, it's absolutely no benefit to you (or at least practically no...