I just purchased G.Skill RipjawsX 8GBx1 1600Mhz F3-12800CL10S-8GBXL few months ago and I am planning to purchase another G.Skill RAM again same as the RAM I have, so that my system will be upgraded to 16GB. I know that what I purchase is a Single Channel RAM since "S" for F3-12800CL10S-8GBXL stands as Single Channel. I am using an Asus P8H77-M LE Motherboard supports Dual Channel Memory. The question is, since I am planning to purchase another Single Channel Memory again "F3-12800CL10S-8GBXL" the same as the Memory I have few months ago. Does it affect the performance of my system using 2 pcs. Single Channel Memory F3-12800CL10S-8GBXL since I am using Dual Channel Memory Motherboard? Or should I purchase "F3-12800CL10D-16GBXL" where "D" stands as Dual Channel Memory and sell the old 8GB I have? Is it because I am using a Single Channel Memory RAM I can't upgrade to 16GB RAM and since it's only for Single Channel and not for Dual Channel? What I mean is that, can I add/upgrade another G.Skill RipjawsX 8GB 1600Mhz F3-12800CL10S-8GBXL Single Channel Memory to make it 16GB (2x8GB) even if I am using a Dual Channel Memory Motherboard? Does a Dual Channel Memory Motherboard supports 2 pcs. Single Channel Memory? 2 pcs. G.Skill RipjawsX 8GBx1 1600Mhz F3-12800CL10S-8GBXL? Thank you so much!