What speed can My motherboard handle? It says 1600-2100(OC) I don't know what that means and if it can handle a stock speed of 1866 or not. Thanks!
It might not auto-configure to the "stock" speed of the modules for compatibility reasons. I have some Corsair Vengeance rated at 2000MHz, but when I first threw these in, they were running at 1333MHz. I looked up the settings, and manually dialed them in through the BIOS/UEFI to 1866, hence the OC. With yours, it would probably auto-configure to 1333 as well for compatibility, but you could manually dial in 1866 settings if need be. It can support up to 2100 if you manually dial in the settings.