Single, Dual, Triple ram questions

lets say i have 4x1 Giga ram sticks

on a dual channel mode, if i put 3 sticks of ram, would 2 of them operate as dual while the other as a single, or would all of them operate as single?

on a triple channel mode, if i put 2 sticks would they operate as dual? or triple channel motherboards only support triple channel?

if i put 4 sticks of ram in a triple channel, would 3 operate as triple channel while the other as a single, or would they all operate at dual channel, or would they all operate at single channel?

thanks in advance.

Well, we need to what type of system you are talking? I7-900 series are the only cpu's that do triple channnel, which requires 3 sticks, 4 sticks will make it run in dual channel mode. All others run in dual channel when using 2-4 sticks of mem and if you use 3 sticks will run in single channel, unless you can ungang the memory. Other than that, that is it.

@surda - How the memory controller reacts to memory that's not evenly distributed across the channels depends on the memory controller. Some of them require the memory to be evenly distributed and others don't. So the answer is: consult the manual.

@Twoboxer - it's not about speed, it's about parallelism and throughput. The speed that the RAM operates at has nothing to do with how many channels there are. If you have two channel memory that operates at speed "X", then the throughput is 2X because you have two of them operating at the same time. But the speed of each is the same, and the speed doesn't change if you remove one DIMM.

It's like saying that cars which travel at 60MPH can drive in only one traffic lane or in two traffic lanes. The speed is the same in both cases, but with two lanes you can move twice as many people per hour.

Don't forget, when it comes to memory controllers, on the AMD's, i5,i7,i9's, they are all on the chip, so it does matter to know what system you are planning on too.