just in case anyone's wondering, I have this same ram in my SandyBridge build and I had to underclock it down to 1.6v for stability. At the stock 1.65v my machine would randomly shut it self off.
i strongly recommend active cooling for this ram or any other high speed ddr3 kit. They get very hot under load and especially running at 1600. I have 24gb of the 8gb kit (3 kits) running in my server and without active cooling it would reboot running prime95 or memtest. After getting a ram fan things are rock solid