Let me help clarify a few things.
You cannot dual channel 3 sticks of ram.
If you dual channel, the ram will be synchronized and work about 15% faster than traditional ram.
Adding more ram only means that more data can be stored in memory.
Benefits: You can run more programs simultanousely without memory constraints
Counterpositives: Your games will not perform much faster
------------------
Dual Channeling memory means the CPU can access the memory faster.
Benefits: Your games will operate much quicker, and load times will be shorter
Counterpositives: It doesn't do much for programs that require a lot of memory; nor does it help if you have tons of programs loaded