Can triple and dual channels run concurrently

[smush]

At the moment I have 6GB in triple channel formation and would like to know if I add another 2 sticks would that mean that I have triple channel and dual channel modes working concurrently? Otherwise what would happen?
Alternatively, if I just add one stick will my 3 sticks still use triple channel?

[KeyboardDemon]

I think they might end up running in dual channel, I don't think you would get triple and dual channel running concurrently.

[0100001]

No depends on motherboard but in 2011 for example it goes dual channel (2 stcks) tri channel (3 sticks) then quad channel (4 sticks). All ram runs at slowest common denominator so using 5 sticks would (i think) just result in ordinary single channel speed

[Professor Frink]

Check you motherboard manual. It will tell you what ram configurations it likes.