|All modules that are installed should be listed as compatible with your mboard model on the ram manufacturer's or ram distributor's web site - if any aren't there's no way of knowing whether they will work properly on their own or in combination with other modules.|
The ram voltage specified for the modules should be the same, otherwise you're likely to have problems with the modules that require a higher voltage - the bios will automatically use the lowest ram voltage for all the ram by default. .
Patriot Viper 6GB (3 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory
Triple Channel Kit
Scroll down - Memory Selector
Motherboard - MSI - X58M
PVT36G1600ELK is NOT LISTED !
CORSAIR XMS3 6GB (3 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory
Voltage:1.65V - voltages of the two brands are the same - good
Triple Channel Kit
Find compatible products - memory finder
Search by Manufacturer's Model Number - X58M
CMX6GX3M3A1600C9 is NOT listed in the default list
Click on "For a complete list of compatible...
CMX6GX3M3A1600C9 IS listed in that longer list
Your problem MAY be caused by the Patriot ram not being 100% compatible with this mboard model !
Modules that are NOT 100% compatible often work fine when installed on their own, but DO NOT work fine when other different modules are also installed !
Also - READ the mboard manual regarding installing the modules.
REMOVE the AC power to the computer AT ALL TIMES whenever you are plugging in or unplugging ram, cards, and wiring connections inside the case !
Sets of 3 identical modules must be installed in specific slots in order for the enhanced features to work (e.g. dual channel)
If ANY modules are in the wrong slots, or if ANY of the modules do not support the enhanced feature, all the modules will still work if they're compatible but the bios will run all of the modules in single channel mode.
Make sure they''re all the way down in their slots and that the latches at the ends of the slots are against the modules.
If any slot is physically close to something such as the CPU heat sink, it may be harder to get it to seat properly.
You may need to remove them and re-seat them.