Dual channel DDR3 RAM question… (Upgrading)

[craige4u]

If in a mobo, out of four available sockets – I fill, 2 x 1GB Ram to run in dual channel mode and then in future add an another single stick of 2GB… will all the total combined 4GB of ram gona run in dual channel mode ? OR only 2x 1Gb sticks will run in dual channel mode and 2GB stick will run in single channel mode?

How this goes ?

PS: All the RAM I am supposed to be buying (Now & future) will be of same speed and manufacturer.
And if you are wondering why I am not upgrading directly to 4GB, as most probably I will go with DDR3 with a new mobo, and DDR3 is quite expensive at the moment…

 

[craige4u]

Anybody ?

 

[ghmage]

If the memory controller was "happy" with different sizes of memory your proposed configuration would work fine.
See http://en.wikipedia.org/wiki/Dual-channel_architecture - an example much like your question is mentioned. In their example, the author uses 2x1gb and 2x512mb.

 

[Calvin7]

FLEX MODE results in both dual- and single- channel operation across the whole of DRAM memory.
Only 2x 1Gb sticks will run in dual channel mode and the 2GB stick will run in single channel mode

 

[Tradesman1]

Put the 2GB in Channel A and the two 1 GB sticks in Channel B (B1 and B2), then you effctively have 2GB in each channel and it runs dual channel......if it were a 4GB and two 1s, then you would have 4GB in dual channel (both 1s and half the 4) with the odd two from the 4 GB stick running in single channel