Quick Dual Channel RAM question

[StrangerGuy]

Lets say I have 2 sticks of 512MB DDR400 RAM and I'm running them on a A64 939 or P4 dual channel setup:

1. If the two sticks are from the same manufacturer, and have the same stock timings, but having different RAM chips, can I run dual channel?

2. Same scenario as 1, except different manufacturer?

3. Same scenario as 1, but different stock timings?

 

[Operandi]

Yes, to all three but I try to match my RAM as closely as possible.

 

[markkleb]

I bought 4 one gig sticks of PQI Turbo ddr400 lat 2 (they are not sold in pairs) and my comp recognizes them as dual channel.

 

[Salacious Sith]

I was under the impression that for the memory to be recognized as dual-channel the sticks had to be exactly the same (manf., amount, etc.).

So this ISN'T the case?