This is taken from your Mobo specs
MSI Reminds You...
• Dual-channel DDR works ONLY in the 3 combinations listed in the table shown in the previous page.
• Please select the identical memory modules to install on the dual channel, and DO NOT install three memory modules on three DIMMs, or it may cause some failure.
• Always insert the memory modules into the GREEN slots first, and it is strongly recommended not to insert the memory modules into the PURPLE slots while the GREEN slots are left empty
• This mainboard DO NOT support the memory module installed with more than 18 pieces of IC (integrated circuit).
• The Maximum memory speed decreases when the following two memory combination is selected:
- Each channel is installed with two double-sided memory module
- Both DIMM1 and DIMM3 are installed with double-sided memory module
• Due to the South Bridge resource deployment, the system density will only be detected up to 3+ GB (not full 4GB) when each DIMM is installed with an 1GB memory module