what.... how can you find out if you NEED dual channel....... We @ TF cannot answer that.
Do you WANT it? And will your board SUPPORT it..
Usually in the POST it says:Memory Running in Single Channel Mode
(dont quote me on that)
something like that should appear. To also verify, open your computer up and see if the ram slots have different colors to them. This would be a good indication of dual channel support. Even better, whip out the manual to the motherboard if its available to you.
And as a word of advice, get the same size sticks, same timings, and same speed, to up the stakes on dual channel compatibilty.
Your best bet is to get the same everything, including the brand.
INTEL i7 930
3x2gb Corsair Dominators
EVGA GTX 480