What is the disadvantage of running an odd number of dual-channel memory modules? Specifically, CORSAIR XMS3 6GB (3 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model TR3X6G1600C8 G on a Giga-Byte GA-H57M-USB3 LGA 1156 Intel H57 HDMI USB 3.0 Micro ATX Intel Motherboard