According to Intel spec; Dual channel DDR can be named as channel A and B. In 8INXP, dimm slot 1 and 3 are channel A, dimm slot 2 and 4 are channel B. Dual channel mode will only work with DDR memory modules inserted in dimm slot 1&2 or dimm slot 3&4. DDR memory inserted in dimm slot 1&4 or 2&3 will only work as single channel mode, and only channel A is available. Memory in channel B will not be detected.