All I can see is there's an additional X2 in the product name of the second but they seem to be similar. Both run at 1600mhz @ 1,65V... And yet there's a 15$ dollars difference? Is this a great deal or am I missing something? I actually already have 2x4GB of the first modules (KHX1600C9D3K2/8GX) so would I be alright for compatibility if I bought the KHX1600C9D3X2K2/8GX?
Note: I would like to run all of my modules @ 1600mhz - 1.65V ; I have an Asus p8z68-v pro and I'm a noob at overclocking (my modules are currently @ 1333mhz - 1.5V by default).
If you already have a kit of the one type, I highly recommend buying another of the same exact kit. Even if the specs seem similar, one type is likely older than the other and may use different memory chips on the sticks. Different memory chips tend to not cooperate with each other.