dual channel question

[damocell]

I have 2 256mb of geil DDR ram as detailed in the below spec. My motherboard manual says to have all 4 Dimms occupied and dual channel still working i need 2 double sided and 2 single sided ram sticks. As I understand it, DDR is classed as double sided, does this the mean that single sided is SDRAM? Is this correct as it isn't made very clear in the manual?
Thanx for the help

[bailey]

no, not really.
ddr is double data rate. which is kinda like the speed it runs at,
twice the data per clock cycle.

double sided is where chips are mounted on both sides of the modual, single is where only one side of the modual is populated with chips.

[bailey]

edit out

[Designer]

I thought your motherboard would work in dual channel with 2 identical DDR dimm's fitted (check manual) but if im right you may have to fit them to other slots like mine has to be in slots 1 and 3 for dual channel to work.