They are keyed differently, to ensure that they can't be used in place of one another. A multiple-banked module allows more flexibility in type of chips used. Multiple banking allows a memory designer to divide the module into banks, which means it can appear to the computer system to be more than one module. Double- sided is a physical term meaning that chips are arranged on two sides of the memory module. Dual-banked is an electrical term meaning that the module is divided electrically into two memory banks.
Gold is a better conductor than tin.
However, because tin is much less expensive than gold, computer manufacturers began using tin sockets on system boards in the early 1990s to reduce their costs. Matching metals can help avoid corrosion. Kingston's policy has always been to match metals, so Kingston part numbers assigned to each computer system take the socket metal into account. The entire organization of rows and columns is called a DRAM array . It has to be refreshed because its memory cells are designed around tiny capacitors that store electrical charges.