"dual channel" DDR matched pairs?

[LotusMan]

Hi-

With dual channel DDR memory, it will operate in dual channel mode when the 2 sticks of memory are the same (same brand, model, configuration, size and speed).

My question is this: In order to operate in dual channel mode, must the memory be "matched pairs" purchased together from the manufacturer? Or, if you have one stick of memory, and you go buy another stock of identical memory (same manufacturer, same model#, etc.) and use them together, will it operate in dual channel mode?

Is there sufficient variation in the production process that 2 sticks of identical memory purchased at different times such that dual channel mode will not work (i.e. memory controller sees them as "different" rather than the "same")?

 

[Bobthelost]

It doesn't have to be bought as a set. I think doesn't have to be the same manufacturer, although it's more likely to work that way.

If the makers switched to a different density set of chips then you'd probably be in trouble. But it's not as difficult / sensitive as it seems at first glance.

 

[Pens1566]

The only safe bet is to buy a 2 stick kit. Do you really want to buy 2 different sticks, only to have them not work together?

 

[stevty2889]

As long as you buy 2 sticks of the same thing, you are almost guranteed for dual channel to work. I've had it work with differant manufacturers. I also ordered 2 sticks of the same thing once, and one of them turned out to be double sided, while one was single sided. Both had the same part number, and the same size. They worked fine in dual channel as well.

 

[Matthias99]

Originally posted by: Pens1566
The only safe bet is to buy a 2 stick kit. Do you really want to buy 2 different sticks, only to have them not work together?

The "dual channel" kits are nothing but two sticks of the same model put in one package (and maybe tested together). There's nothing special about the RAM you're buying. As noted, just about any two sticks of RAM the same size/speed can be used -- working with single/double-sided on the same channel is a little extreme, but apparently even that works in some motherboards.

Buying "dual channel memory" is kind of like buying "four-wheel drive tires". It's not the RAM that determines whether you can run in dual-channel mode.