I have heard of people even getting sticks of different brands to run dual channel. the point is, that if you have matched sticks, you are pretty much guaranteed it will run dual channel. If they are the same but not bought as a matched pair, they have a high chance of running dual channel but there is enough variation between batches, even if the same components are used on the memory, that there is a small chance they may not run dual channel. anything beyond that, it is a gamble weather it will work or not. some motherboards are pickier that others what they will run dual channel. You can have the same exact parts and it might work in one system but not another if the memory is not the same.
As far as timings, if I understand right, the two sticks have to be able to run the same timings (even if they are rated at different timings). A faster stick might be able to run slower timings to match the other slower stick, but again, its a gamble.
I just googled this if you want something in writing to show someone.
according to that kingston link in that post, this is what is required.
In this context, â€œmatchingâ€ modules means:
1. Both modules are the same capacity (e.g. both are 256MB, or 512MB)
2. Both modules are the same speed (e.g. both are PC2700 or PC3200)
3. Both have the same number of chips and module sides (e.g. both have the
same number of chips on the module, and both are either single-sided or
I think that experience tells us that the above conditions are sometimes, but not always enough, particularly with some motherboards (asus had a few boards a while back that were insanely picky from what I hear).