Single sided or Double-sided is a physical term describing the arrangement of chips on one side or two sides of the memory module.
Double-Sided Memory refers to how the module is physically built with the individual memory chips. In this instance, they are placed on both sides of the PCB.
Singe-sided memory modules are newer and the chips are denser, enabling more capacity. Earlier 16 chips were used to make a 256M module, now it takes eight chips. Older motherboards may not recognize single sided memory.
DDR RAM and Rambus RDRAM are the RAM's that come in single-sided memory versions.
